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Nv4500 tech

Oddball

Oddball

Well-known member
Joined
Nov 23, 2021
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4569
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358
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Canaderp
I've done a lot of research on the NV4500 when I picked up this transmission and found that it had a broken gear. The piece was nowhere to be found so I was kind of dooped. But, I new it needed an input shaft and the broken gear was the one that meshed with the input. So, I went about tearing it apart. It's a 95 ( as far as I can tell) GM box with the multi-piece counter shaft. I found that there is not a lot of real tech on this trans. Basically, just vids and write-ups on the 5th gear problem and some basic factory specs. I did find info regarding making it " bullet proof " and that is what I'd like to talk about. Tractor pullers weigh in. When reassembling it, I found that the factory calls for 2-6 thou end play. That to me is crazy. To give tapered rollers end play is to invite problems. I did find one forum post that suggested as close to zero as possible. And so, that's what I did. I havent used the trans yet, so I don't know if following my gut was a mistake. But, when spinning things by hand, all the weird noises went away. I read about third gear failures and it makes sense if you allow end play. Would you give wheel bearings or a third member end play? Ofcourse not. So, why would you do it in a transmission? I haven't been able to talk to anyone about this, so it has remained in the back of my mind. What do you guys ( and gal..I'm sure there is one) think? Did I make a bomb or am I brilliant? Finally, it did have a loose 5th gear and so I rigged it...I'm cheap ok. The GM trans has a big dampener on the output that splines on and it was still a good press fit. So, I welded fifth to the dampener and green thread locked it on. Ya I know. Any other secrets you can add? I'd like to collaborate all the tech into one post. I will update this post when I get my project on the road. Donations welcome lol. You can see the build thread I started in the Toyota section. Thanks Gang.
 
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Well that is the wild card isnt it. Everything should be not much hotter than the oil. Including the case. So the case will expand as well. When the trans is under load it will be spreading the case. Which will open the end play.
 
Ive never touched a working trans that wasnts to hot to touch/hold a hand against. So they dont get THAT hot +150*ish.

I know the "diff" temp gauges typicaly top out @ 300*

We have a bearing heater at work and the rule is .001" / diam inches / 100* to slip fit a race onto a shaft.
Would be interesting to see what happens to a roller heated to 250*ish.
 
Finding the bellhousing I want is my major issue.

I found many flaws with the Advance adapters bellhousing with the application im running and only a actual steel bellhousing will seem to work.

The fact that there are two transmission bolt patterns are also an issue that it seems a majority of parts monkeys dont know about, they think if its called a nv4500 it will fit all nv4500's.
 
What bell housing are you looking for?
 
Oddball said:
I found that the factory calls for 2-6 thou end play. That to me, is crazy, to give tapered rollers end play is to invite problems. I did find one forum post that suggested as close to zero as possible. And so, that's what I did.
Click to expand...
heres another if this isnt the one you saw already

Again, can't run them loose. But you can't run them tight. I take all of the end play out and have always. It works for me, and I don't have bearing failure.

By the way, there is a document out that explains the revised bearing setting specs. Sorry I don't have one anymore.

If you can get away running the bearings loose, GO for it.
Click to expand...
www.turbodieselregister.com

nv4500 preload specs

does anybody have the factory specs for the nv4500 bearing preload
www.turbodieselregister.com www.turbodieselregister.com
 
Grendel said:
What bell housing are you looking for?
Click to expand...
Preferably a Quicktime chevy to early 4500.

This one

download.jpeg




Need an attachment for external slave and a standard gm ball stud mount.

They produced one a few years ago but it was for the early pattern.

It would be a major PITA to ruin a spendy disc with a oil leak from a cheap internal slave and it would create more labor to be required to pull the trans for a leaky internal slave.
 
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rockyota83 said:
Again, can't run them loose. But you can't run them tight. I take all of the end play out and have always. It works for me, and I don't have bearing failure.

By the way, there is a document out that explains the revised bearing setting specs. Sorry I don't have one anymore.

If you can get away running the bearings loose, GO for it.

www.turbodieselregister.com

nv4500 preload specs

does anybody have the factory specs for the nv4500 bearing preload
www.turbodieselregister.com www.turbodieselregister.com
Click to expand...
Yea that's the one. That post seems pretty creditable.
PAE said:
Finding the bellhousing I want is my major issue.

I found many flaws with the Advance adapters bellhousing with the application im running and only a actual steel bellhousing will seem to work.

The fact that there are two transmission bolt patterns are also an issue that it seems a majority of parts monkeys dont know about, they think if its called a nv4500 it will fit all nv4500's.
Click to expand...
Mine is the early bell with the small bolt pattern and external hydraulic slave. That actually makes it a 94 doean't it? But it has the 5.61 first not the 6.34. I think it's been monkey'd with numerous times. We will see if that extra casting for the slave gets in the way of the front driveshaft. It appears a guy could redrill the bottom two bolt holes for the larger bolt pattern. Maybe ill have to pull the trans and find out.
 
92-95 GM is the early and yours also has a different diameter bearing retainer diameter.
 
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PAE said:
92-95 is the early and yours also has a different diameter bearing retainer diameter.
Click to expand...
Thanks, I was just going to correct myself. It's been a while since It was fresh in my mind. So basically, even if you can redrill the case for the larger bolt pattern, you would still have issues centering the bell.
 
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One could have a ring made with a step (shoulder) but dont remember which was the larger, early or late.
 
That would work best, maybe ill just buy the early QT if everything lines up.
 
PAE said:
That would work best, maybe ill just buy the early QT if everything lines up.
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What NV do you have? When you say early QT, do you mean 92-95? Seems like you can put a late model bell on an early case, but not the other way around. And The throw-out bearing would be another issue.
 
The early/late bell bolt pattern...

AFAIK, it's just the two lower holes that differ, and there's enough meat on the trans to drill.
 
I have a 95 and a 96+ 4500.

Ill find and post the 4500 bolt patterns.


earlyNV4500.jpeg


LateNV4500.jpeg
 
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PAE said:
I have a 96+ 4500.

Ill find and post the 4500 bolt patterns.


earlyNV4500.jpeg


LateNV4500.jpeg
Click to expand...
Yea so an early bell will not work on a 96 case. The center is to small. You could possible have the bell bored out. But the throw-out bearing will still be an issue I believe. I don't think the internal slave style has a snout.
 
I have the bearing retainer for the dodge transmission used with the chevy 1.250 input but the slave cylinder is in the wrong location on the setup in your pics.

Still need the QT bellhousing, need the clutch fork location at 9:00 from rear perspective.

Would rather drill the bell than the transmission.
 
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Dont know if the pattern will expand and or is worth buying the early bell and drilling the two extra bolt holes in the bell.

No room from the look of it.
Eta nope not enough seperation to have another seperate bolt pattern, they intersect.

20211214_205616.jpg
 
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PAE said:
Dont know if the pattern will expand and or is worth buying the early bell and drilling the two extra bolt holes in the bell.

No room from the look of it.
20211214_205616.jpg
Click to expand...
You would most definitely want to drill two new holes in the casing. Maybe you can adapt an early bearing retainer with the help of a custom hubcentric ring and ovaled mounting holes. Or turn the retainer 45 degrees and drill/tap four new holes. Then regrind the oiling passage at the new top of the retainer. You would need to reshim the the bearing also. Looks like you could get away with a 1/16th shim behind the front race.
 
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Not sure what your end use is. Mine is in my Cummins powered tow rig. I set my end play on my first one to zero. It would run typically 180 degrees over ambient temperature while running loaded in 5th. Got about 40,000 miles on that trans before it ate the bearings. Next trans I set to .003. Temps are 120deg over ambient under the same conditions and it shifts smoother.

Did you add the green locktite before you welded or after?
 
The bone stock NV4500 with factory end play will live a long life behind your LM7.…. with disappointing results. It’s a slow shifting trans.
 
An M22 would be nice (as for faster shifting) but unsure if it would live long with the LM7 horsies and in short supply last one I had was behind a Big block Chevy in a 1967 Camaro.


And beyond that the 4500 is meant for a truck not a sports car.

TrailTamer said:
The bone stock NV4500 with factory end play will live a long life behind your LM7.…. with disappointing results. It’s a slow shifting trans.
Click to expand...
 
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They make short shit spacers for bolt on shifter tops.

I know top swapability was discussed at some point but i forget what the situation was.
 
fvs said:
Not sure what your end use is. Mine is in my Cummins powered tow rig. I set my end play on my first one to zero. It would run typically 180 degrees over ambient temperature while running loaded in 5th. Got about 40,000 miles on that trans before it ate the bearings. Next trans I set to .003. Temps are 120deg over ambient under the same conditions and it shifts smoother.

Did you add the green locktite before you welded or after?
Click to expand...
After. I pressed it all on, tacked it good, removed it to finish weld and then green'd it back on. Future me will be pissed.:homer: Thanks for the real data. Ill be sure to run a trans temp gauge. End use is turbo toyota with danas and low low. So light rig and no pulling.
TrailTamer said:
The bone stock NV4500 with factory end play will live a long life behind your LM7.…. with disappointing results. It’s a slow shifting trans.
Click to expand...
My end game is boost until clutch slip then back it off a C-hair. Ill be happy with 500 whp. I don't think there are many manuals that can take that power level. I couldve got a getrag, but passed on it thinking it wasn't strong enough. I hear the 4500 shifts better than any 4speed. Im to poor for a sixer. And autos are gay:bert:
 
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