1995 f350 tranfercase/transmission woes

[Tiha]

I tend to overthink things. So here is my latest attempt.

1995 F350 diesel 4x4.
E4OD and 1356 transfer case.

Recently I discovered that I have a shift fork problem in my TC, wasn't too worried about it because I couldn't find where that caused other issues as long as was able to get it back into 2 hi. Which I did.

I have an E4od that I have been gentle on for a while thinking it was close to the end.

never the less I had a trip. Pulling a trailer and no time to swap TC.

Trailer is only 3-4 thousand pounds not a heavy load. Right from the start my trans temps were high, like 220. Reaching 240 on hard pulls. So I backed out of it and shut the chip off. That kept trans temps down 200-210. I could live with that.

Cruising along all is well, then 500 miles into the trip and pop. Grinding noise, no forward gears. Hit the shoulder.
Put TC in 4 lo hoping to limp off interstate. It worked. Got to parking lot and played a little bit.
Switched TC back to 2 hi and I had forward gears again. Hmm.

Did it just pop out on a big bump?

Take off again, 20 miles down the road, neutral again. Same routine, side of the road, 4 lo, off highway.

Playing with it I had 4 lo, could not get back into 2 or 4 hi. Okay so TC is toast. right?

BUT trans shifts 1-2 and tries for 3 and pops right back into 2. 1 and 2 hold great. OD light started flashing, tried to pull codes, showing no codes. Thinking maybe a chip issue I pulled the chip. No change.

Settled on the fact the truck is not moving very far, parked it and got a rental.

Now truck is home. Diag time.

Trans fluid not burnt. Still clean, full, and new looking.

TC fluid burnt bad. Full of fluid but burnt. I feel something laying in the bottom sticking my finger in the drain hole. Not surprised because I already knew there was shift fork issues right?

So questions?
Can the TC cause my increase in Trans temps?

Can it have anything to do with my trans not wanting to shift above 2nd gear? ( I don't know how, but I am just a mushroom)



I'll probably open the tc tonight and see what I see, but expecting full rebuild or replace.
Was planning on Stage 4 E4OD kit but now I am not so sure. If it held up this long to all the abuse then maybe it doesn't need the stage 4 kit, but rather just a refresh and some updates. I would hate to put in parts of lesser quality than what it is in there already.
I'm on my third torque converter already and I think this one is good. I have an inline trans filter I need to cut open and see what is in there. That will help determine how far to go on trans I suppose.

 

[RustyC]

It is logical to say the popping out of gear would be shift fork related. It is also logical to say that the t-case issue would not cause the transmission to overheat and or log a code. I have a feeling you are going to have to rebuild or replace both. Not sure if you are gas or diesel but I opted for a 1350 stall converter for my 7.3 superduty. I absolutely love it.

 

[Tiha]

It is logical to say the popping out of gear would be shift fork related. It is also logical to say that the t-case issue would not cause the transmission to overheat and or log a code. I have a feeling you are going to have to rebuild or replace both. Not sure if you are gas or diesel but I opted for a 1350 stall converter for my 7.3 superduty. I absolutely love it.

Diesel, yes. and I have to agree with you. I don't see how either.

If I end up with a Stage 4 kit for the trans a low stall converter is on my list. I hear great things about them.

 

[Tiha]

Tore into the transfercase last night. It is pretty bad. Looks like the pump brace/leg failed. No pump, no fluid flow.

The chain gear spun dry on the output shaft. Both parts are junk. Both shift forks broken. Chain was rubbing on the case. Thought I was looking at a $500 rebuild. Check fakebook and found a TC from 88 for $100.
Grabbed it, tore it open thinking I will get some of the parts I need and it looks like brand new inside. So will do the pump mod and seals, that is about it.

Interesting note, 1995 had plastic shift fork for 4hi, ( I think, the rear one anyway) and the 1988 had an aluminum one.

Other side note, so I had a gear vender on the back of my old TC, before this trip I noticed it spit a bunch of oil out the vent. Not having time to dig into it, which it can be difficult to get parts for anyway, I just pulled it and put my old driveshaft back in.

I do think the TC caused the GV and transmission to overheat. The transmission has to have some damage now so It is coming out next.

 

[bobbywalter]

well...you covered what i was going to say. that the pump fails and the case binds as it murders itself from lack of lube. trans does not want to stay locked and converter heat builds....if it is a stock converter they peel off friction material pretty quick at 240.

since fluid looks good and is not fried and full of clutch from your observation....

if the shift solo 1 is stuck open....or died open it wont shift past second. heat load may have had material/varnish cause 2-3 shift valve stuck..... or blew a gasket or simple retorque from the high heat load on the old beast is in order.

 

[Projectjunkie]

A bad alternator letting some ac thru with the dc voltage can cause problems like that in a e4od and dodges, haven't seen it in gm trucks

Charge battery, pull the charge wire, isolate it and see what's up

 

[AK_F250]

A bad alternator letting some ac thru with the dc voltage can cause problems like that in a e4od and dodges, haven't seen it in gm trucks

Charge battery, pull the charge wire, isolate it and see what's up

A problem with the brake light circuit can fuck with them too, at least lockup. Chased that one for a long time before I realized it was the damn led tail lights causing the issues

 

[Tiha]

The pump failure in the 1356 transfercase cause the transmission to run hotter. I know that for certain now.

New case has modded pump bracket and gets new seals today.

The E4OD is torn down and looks completely brand new inside. I found some metal/abrasive material in one of the valve body passages but haven't found the source. The clutch packs all look new.
Never the less, my shifting problem is probably a solenoid/valve body issue. I will take care of that while I freshen the trans.

Probably use a tugger kit, or the Sonnax zip kit. Can't decide which one yet. I want the torque converter lockup to feel like another gear, quick and firm. I am not sure if going to a triple disc clutch is enough for that or if I need to do VB mods as well. The sonnax kit has Converter mods, I don't see where the Transgo kit mentions it.

Was going with a stage 4 kit but now probably just an extra clutch kit with updated 45 sprag and bushings.
Heck the extra clutch kit might be too much, if I haven't hurt this thing by now I seriously doubt anything I can do in the future will.

 

[subybaja]

well...you covered what i was going to say. that the pump fails and the case binds as it murders itself from lack of lube. trans does not want to stay locked and converter heat builds...

The pump failure in the 1356 transfercase cause the transmission to run hotter. I know that for certain now.

Can you explain the relationship here?

It seems to me the Tcase could be completly FUBAR, full of rocks and gear pieces, and the trans would just see it as an extra 5hp drag.

Torque converter locked or unlocked has nothing to do with the Tcase...right? Bad converter/clutches will certainly kill the trans, but unrelated to Tcase.

Two separate gearcases, separate oil supplies, and the trans has a cooler, so I can't see heat from the Tcase being much of an issue, especially at road speed...? I've been through a roached 1356, and I can't see a 2" shaft with a bad bearing making enough heat to cook a trans 2' away...

I don't get it. Seems like two separate failures to me.

 

[Tiha]

Can you explain the relationship here?

Okay, I will add a disclaimer,
I am convinced in my set of circumstances that the transfer case was the cause of the increased heat levels in my transmission, may not be the cause of heating issues in other people's equipment configurations.

The reasons I believe this.

This process started with my Gear Vendor that was on the back of the 1356. I roll under the truck looking it over before a trip, I notice the GV has blown a bunch of oil out of the Vent. Without much time and the difficult process of obtaining parts for GV units I opted for removing it and running this trip without it.
Upon tear down and inspection of the GV unit I can find nothing wrong and no cause for excessive heating. At least to the point that it was blowing fluid out of the vent. I have had the GV for 100k miles, I have been into a few time and am quite familiar with them. Having trouble with it before I had no problem believe it was failing again.

At this point my trans temps were still fine.

Moving the truck while the rear drive shaft was removed I realize that the transfer case is not functional in 4 hi. But 4 lo works. Checked oil level on the Tcase, a little dirty but full.
Scouring the internet (first mistake) on if it was safe to continue to drive with a busted shift fork or not. I came to the conclusion that it will be okay as long as I can get it back into 2 hi and leave it in 2 hi. Since the fluid at this time was not burnt I ran under the impression that it will be okay. After a couple shorter 30 minute road trips everything appeared to be functioning correctly.
(At this point I had not torn into the gear vendor for inspection)

Take off on trip, first 60 miles or so all is well. Then trans temps start climbing. Not spiking, but climbing slowly to stable levels well above normal. On a transmission that has always ran 180 degrees cruising down the road for the last 170k miles, I was now seeing 220-240 pretty standard. It was gradual first 200 seemed to be the new normal, then 210, then 220. Then we hit a rain storm and back down to 210. I am thinking bad sending unit or plugged cooler or something. Then 230 is the new norm and then 240 on the hard pulls. Then bam no forward motion in 2 hi until truck cools down for an hour.

Upon tear down and inspection this transmission with 170k miles on it is perfect, pan is clean, magnet is clean. Fluid is clean. There is no sign of slippage or high temps anywhere.

Upon tear down and inspection of the tcase the pump is broken, spinning freely with the output shaft. Oil pickup hose is broken. Fluid is burnt badly. The chain gear and output shaft are worn so badly that the chain was rubbing on the case. The gears and shafts are discolored from being extremely hot. Probably glowing red hot.

So to me the logical conclusion is that the Tcase was the source of the heat and it was transmitted through the aluminum housings to both the gear vendor and the transmission.

At what temperature would the gear or output shaft discolor? 300 degrees? 400? 600?
So the extremely elevated TC temps transferred 100 degrees? into the transmission housing? Adding 40 degrees to my fluid temp?

I mean that is possible right? Maybe it transferred 200 degrees into the trans case. Would have been interesting to know but too late for that.

Hoping the transmission shifting issue I thought I had at the end was created by the excess heating. As heat goes up, so does resistance in the solenoid pack which is at the back of the trans. Or maybe the aluminum valve body swelled enough to stick a steel spool valve in the valve body. I will figure that out soon enough.

From start of trip to implosion of the Transfer case was about 9-10 hours. Tucked up under the cab, steady radiance and conductance of heat. I guess I think it is totally believable.

You also have to remember this is a diesel, The down pipe is ceramic coated and heat wrapped to the back of the trans, but that is still adding a bunch of heat pretty constantly under the truck heating the air around the trans and t case. My pre turbo temps are 1000-1100 most of the time.(I was towing) The down pipe is not 2" from the transmission. So I didn't have any fresh air cooling under the cab, but the down pipe has never created issues by itself before.

That's my story and I'm sticking to it. But would be happy to hear if I am wrong so I can correct the real problem before I start putting this thing back together.

 

[Bigblue 94]

I was thinking the transfer case binding was the root cause of the whole situation. This causes resistance in the transmission which heats up the converter and fluid. This may also be why it wouldn't shift right, as there was too much load on the output shaft.

Steel generally turns to a straw color at 350° F. Look up a heat tempering chart for steel for colors and related temperature.

 

[bobbywalter]

Can you explain the relationship here?

It seems to me the Tcase could be completly FUBAR, full of rocks and gear pieces, and the trans would just see it as an extra 5hp drag.

Torque converter locked or unlocked has nothing to do with the Tcase...right? Bad converter/clutches will certainly kill the trans, but unrelated to Tcase.

Two separate gearcases, separate oil supplies, and the trans has a cooler, so I can't see heat from the Tcase being much of an issue, especially at road speed...? I've been through a roached 1356, and I can't see a 2" shaft with a bad bearing making enough heat to cook a trans 2' away...

I don't get it. Seems like two separate failures to me.

The assumption of 5hp drag is the problem.

Converter running unlocked or slid out is 20 degrees unladen. Shuttling is worse.


A t case running 250 degrees instead of a 110 or 120 is a huge factor. At 240 degrees it's dragging pretty good.

Any throttle modulation will cycle converter lock


On stock converters. .if it shudders, replace it as soon as you can ...

These units with oem power go over 400k with 1 or 2 converter changes.

 

[Tiha]

Thanks for the info guys, that is very reassuring to not be the only one to think this could happen.

I will add in my case, the torque converter was not unlocking.

This is my third converter, so I was familiar enough to watch the RPM gauge and check for slippage. I could not detect any.

Transfer case binding would explain a lot, I thought I was running more EGT and pedal than I should have been for the load.

I think I wish the output shaft would have just snapped off then I would have known the problem, got it fixed locally where I broke down and went on with my life.

 

[bobbywalter]

my temp gun gets a work out whenever i stop.


even 1 percent slip makes stupid heat....not as bad as unlocked, but at least its not wiped out.

 

[arse_sidewards]

my temp gun gets a work out whenever i stop.


even 1 percent slip makes stupid heat....not as bad as unlocked, but at least its not wiped out.

Yeah, but how many millions of C6s were just fine running unlocked all the time? Slipping or running unlocked shouldn't roast a trans. Heck they even give you a button so you can force it to stay unlocked.

 

[Tiha]

Yeah, but how many millions of C6s were just fine running unlocked all the time? Slipping or running unlocked shouldn't roast a trans. Heck they even give you a button so you can force it to stay unlocked.

Not really the same setup. You are correct that the C6 ran unlocked. BUT it had a torque Converter designed to run unlocked.

The Lockup converters generate an enormous amount of heat unlocked because they were designed to be locked. I don't know the specifics of design and efficiency changes but I do know they are two completely different setups.

They do not give you a button to lock out the torque converter, at least Ford and GM never did. In fact, in the past they have installed a temp sensor to do just the opposite, that is lockup the torque converter in extreme heat scenarios to help cool things down.

 

[Bigblue 94]

Not really the same setup. You are correct that the C6 ran unlocked. BUT it had a torque Converter designed to run unlocked.

The Lockup converters generate an enormous amount of heat unlocked because they were designed to be locked. I don't know the specifics of design and efficiency changes but I do know they are two completely different setups.

They do not give you a button to lock out the torque converter, at least Ford and GM never did. In fact, in the past they have installed a temp sensor to do just the opposite, that is lockup the torque converter in extreme heat scenarios to help cool things down.

Many guys towing with the E4OD back in the day installed a toggle switch to manually keep the converter locked for heat mitigation. And keep it locked, it will. If you come to a stop with the converter locked, it acts like a clutched vehicle and dies. The switch simply grounds and completes a circuit. The wire in question is purple with a yellow stripe in the trans control harness.

 

[arse_sidewards]

Not really the same setup. You are correct that the C6 ran unlocked. BUT it had a torque Converter designed to run unlocked.

The Lockup converters generate an enormous amount of heat unlocked because they were designed to be locked. I don't know the specifics of design and efficiency changes but I do know they are two completely different setups.

They do not give you a button to lock out the torque converter, at least Ford and GM never did. In fact, in the past they have installed a temp sensor to do just the opposite, that is lockup the torque converter in extreme heat scenarios to help cool things down.

The fuck are you smoking? The OD button on an E4OD locks out 4th, keeps the converter from locking up and keeps the coast clutch solenoid on/off (I forget which but the point is it won't let the truck coast faster without pushing the engine faster). It makes it behave like an old 3spd. If they weren't capable of running unlocked then they wouldn't give you that option. Yes, some newer vehicles are different but that's not what we're dealing with here.

Many guys towing with the E4OD back in the day installed a toggle switch to manually keep the converter locked for heat mitigation. And keep it locked, it will. If you come to a stop with the converter locked, it acts like a clutched vehicle and dies. The switch simply grounds and completes a circuit. The wire in question is purple with a yellow stripe in the trans control harness.

I know about that. They also lugged the shit out of their engines. If the trans couldn't survive being run unlocked Ford wouldn't give you a button to do just that from the factory.

 

[reptillikus]

Wtf are you talking about. The OD button on an E4OD turns off OD. Thats it.

 

[arse_sidewards]

Wtf are you talking about. The OD button on an E4OD turns off OD. Thats it.

It also keeps the converter from locking and keeps the trans from freewheeling (only matters in the lower gears IIRC)

 

[reptillikus]

It supposed to apply the coast clutch solenoid in all 3 gears, but the converter still locks and unlocks like normal.

 

[bobbywalter]

It also keeps the converter from locking and keeps the trans from freewheeling (only matters in the lower gears IIRC)

No.

And it's 20 degrees or so. Unless laden. That 20 degrees isn't going to kill a trans if it running 200 or 210....just more fuel wasted and more trans fluid wasted from frequent changes.




Being unlocked don't kill it...just builds heat.

And yes many many c6 burned up over loaded.

Far from bullet proof. They never had serious power put through them towing 20k. We're no 800 ft lb u hauls....with c6.

Put a modern diesel in front of a stock c6 from a 6.9 idi and it will rip it's guts out pulling it's rated load ....rapidly..

 

[arse_sidewards]

No.

I'm 99.999% sure it's in my '94 FSM.

And yes many many c6 burned up over loaded.

Well yeah. They made millions of them. Point is they didn't all shit out below 100k like all. the "muh locked converter" morons would have you believe.

Put a modern diesel in front of a stock c6 from a 6.9 idi and it will rip it's guts out pulling it's rated load ....rapidly..

Bullshit. It's barely different than the first three gears of an E4OD or 4R100. If you cool it the same way you'd cool an E4OD with that engine you'd be fine. The reason people burn up C6s when they turbo and turn up their old diesels is because they don't give the trans the cooling it should have for that horsepower level.

 

[Tiha]

I'm 99.999% sure it's in my '94 FSM.

I certainly appreciate your enthusiasm but you may want to recheck that manual. You are the only person saying that the OD button locks out the converter.


Maybe my converter was slipping but not unlocking, and adding to heat. the more I think about it, that is certainly a possibility. I haven't cut my inline trans filter apart yet to see what is in there. We'll never know for sure as I have an eagle triple disc on order from racer X.

Interesting if an unlocked converter only generates 20 degrees more heat, never hear anyone claim that. I remember the 6.2 diesel with a 700R4 behind it. If the load or grade was enough that the 6.2 could not get enough speed to lockup and hold the converter that was all it took to toast it. Like one 30 minute run. Maybe it was a lack of cooling. Don't remember if we were adding huge coolers or not. But that is the world I grew up in.

We burnt up a few C6s behind stock 6.9 diesels. It was to the point that we stuck an allison behind the 6.9 instead of putting another c6 back there. It was awesome, it would chirp the tires shifting between all 6 gears. LOL.

This was 84-87 and the one big thing we learned was those engines the 6.9 and 6.2 would operate and generate peak torque at an rpm lower than was the transmission pump was designed to operate at. Which they of course were originally designed for a gas engine. Not operating at peak rpm for the transmission pump meant less pressure and less flow.

Would have been nice to have the information available via internet back in those days. But nope we had to figure it out ourselves and fail frequently.

 

[reptillikus]

I certainly appreciate your enthusiasm but you may want to recheck that manual. You are the only person saying that the OD button locks out the converter

The manual states that the coast clutch is applied in all gears, and the converter will lock and unlock as normal.

I think Bobby is correct on the temp increase w/ the converter unlocked. From what ive seen when having issues with lockup in an E4OD, the temp seemed to run ~20º when sustained unlocked. Of course thats an approximation and im sure it would vary slightly from vehicle to vehicle.

 

[Tiha]

I have an inline, spin on filter. It is 30 micron. It is located on the return from the trans cooler before the line enters the transmission.

Cut it open today. Found metal flake. Could not identify any clutch material from the converter clutch like last time.

So now, where did it come from?

If my understanding is correct it can only be one of two things.
Another failing converter?
Or
It is being flushed out of trans cooler into filter from the last failure?

They say it is hard to clean out coolers but it was flushed and external cooler replaced after last converter change and that is when this spin on filter was last changed.

Any theories?

My other two converter failures you could see it in the tach and you could usually hear it. Found clutch material in the filter both times.

Maybe a bearing failure in the converter?

I kinda want to cut it open and see but Racer X wants my old one for a core. Too bad I threw the last one away I could have sent him that.

 

[Tiha]

Just FYI, I drained the Torque Converter into a clean white bucket, siphoned the oil off and it was clean. Nothing in bottom at all, meaning it was ok and not throwing the metal shavings.

So when someone tells you to replace external and flush the Trans cooler, believe them. Crazy how much must have been left in there after a bunch of flushing.
Now I am wondering if I should replace the external again.

 

[Tiha]

Thought I would update this with some actual temps after getting it back together.

According to the IR gun on a rebuilt 1356 filled Mobil 1 synthetic atf. It was 130 degrees f after driving around mixed highway/ town in 2 hi. 20 miles probably.

The pan of the trans was 180.

The case of the trans bell housing area was 195.
Overdrive area of case 215
Intermediate/direct clutch area 205
Reverse area of the case 205.
Inlet to trans cooler was 195.

Just some numbers to help others troubleshoot someday I hope.