Expense. Find me another with TAK-4's for that price and it'll happen. 8x8 starting bids have been around $30k for the last year that I've been looking.
We were all set to buy the firetruck. Even had my route picked out. Found out that the Timoney suspension on it uses an early AxleTech planetary hub that was highly prone to cracking, hence the 30mph speed limit sticker on the dash. We skipped bidding on an AxleTech 4500 in California to wait out on the firetruck. Ditched the firetruck due to the hub issue and lack of support. Two more AxleTech 4500's were up for auction and we couldn't bid because of everything going on with the virus and the fact that we couldn't register the F350 we just bought. Moments after I got insurance on the F350, I got a call from PurpleWave saying that the winner bidder of the Isuzu was not paying and that we could have it for $3200 - right after we paid $5k for the Ford. All good. We got a four door with good power and a stout rear.
That's only about half of it, but covers it well. I'm dead set on putting independent suspension drive axles on. Definitely if we could find a complete, running vehicle that isn't on the other side of the country and within out budget. So far, the axle units themselves are by far the cheaper option and driveshaft sections sell for dirt cheap.
For driving the front axle , have you considered hydraulic?
With a pump running off the front of the T case and a hydro motor on the pinion?
That would eliminate the driveshaft and eliminate the tire scrub since the hydro would not be a direct drive.
I assume hydro motors large enough are available somewhere ?
Or maybe a generator on the t case and electric motor on the front axle pinion ?
roundhouse said:
For driving the front axle , have you considered hydraulic?
With a pump running off the front of the T case and a hydro motor on the pinion?
That would eliminate the driveshaft and eliminate the tire scrub since the hydro would not be a direct drive.
I assume hydro motors large enough are available somewhere ?
Or maybe a generator on the t case and electric motor on the front axle pinion ?
Hydro steer/drive axles are commercially available. Just stupid $$$
roundhouse said:
For driving the front axle , have you considered hydraulic?
With a pump running off the front of the T case and a hydro motor on the pinion?
That would eliminate the driveshaft and eliminate the tire scrub since the hydro would not be a direct drive.
I assume hydro motors large enough are available somewhere ?
Or maybe a generator on the t case and electric motor on the front axle pinion ?
Hey, you're on to what I was thinking about around a year or so ago. Hydro might not hold up to highway speeds that well. I'm still considering electric drive because that would be light and full of torque and capable of the highest RPM I'll need. Been considering a Detroit genset generator that bolts up the the engine and provides plenty of kilowatts to drive all motors that drive the axle pinions. Still really expensive, though. TM4 has motors that match what I need.
T-cases and drive shafts are alright. Cheap, but really heavy and need fairly constant maintenance. None of the axle or t-case ratios are working out for highway speed without stacking overdrive ratio t-cases which adds up to a couple thousand pounds.
JNHEscher said:
Hey, you're on to what I was thinking about around a year or so ago. Hydro might not hold up to highway speeds that well. I'm still considering electric drive because that would be light and full of torque and capable of the highest RPM I'll need. Been considering a Detroit genset generator that bolts up the the engine and provides plenty of kilowatts to drive all motors that drive the axle pinions. Still really expensive, though. TM4 has motors that match what I need.
T-cases and drive shafts are alright. Cheap, but really heavy and need fairly constant maintenance. None of the axle or t-case ratios are working out for highway speed without stacking overdrive ratio t-cases which adds up to a couple thousand pounds.
What if you drove a pump off of the output of the rear tcase, then used a motor on a front tcase (to allow disconnecting the motor when not needed)?
You could fix any front to rear ratio issues with the pump vs motor displacement ratio.
Just get this . stretch the frame and put your bus on top
Or the civilian equivalent
I’m sure there’s some electric utility company trucks that would have highway ratios
Kinda want to. Those TAK-4 suspension axles under it typically sell for around $500 brand new and weigh something like 4,000 pounds each, but they all have the steering parts and tandems have the bevel gear center diffs. Not too sure about $11k.
There's a bunch of those here in Colorado on auction. They're all straight axle. Probably slow as molasses.
aczlan said:
What if you drove a pump off of the output of the rear tcase, then used a motor on a front tcase (to allow disconnecting the motor when not needed)?
You could fix any front to rear ratio issues with the pump vs motor displacement ratio.
Aaron Z
To do 75mph (and I will), the 5.64 AxleTech ratio pinions would spin at about 3,500rpm and the 6.0 TAK-4 ratio pinions would spin at about 3,700rpm. I'll see what I can find to make that work just out of curiosity.
JNHEscher said:
To do 75mph (and I will), the 5.64 AxleTech ratio pinions would spin at about 3,500rpm and the 6.0 TAK-4 ratio pinions would spin at about 3,700rpm. I'll see what I can find to make that work just out of curiosity.
Do you need to have 6WD/8WD on when going that fast? If not, you could use a lower speed rated motor that would be good for say 1600-2000RPM.
If you do, look at this motor: https://www.surpluscenter.com/New-Ar...or-9-12680.axd
Single rear axle drive on the highway. Maybe front axle only for in town. Kinda voting for 8x8 overall for the safety factor because when a steer tire blows out on a bus or RV, shit hits the fan in a hurry. Extra upside is less distance between fronts and rears, so high centering is less of a worry.
That motor would be sweet. Might be a little shy on torque handling, no? 1,240 lb. ft. at the crank. I'll have to see if I can find how much torque is applied to the 3.33 Rockwell pinion to get about 30,000 pounds rolling from a stop.
bdkw1 said:
Yes. There was a guy on here that did mining equipment in Canada, they used them on some trucks. Had some useful info on them.
Rocky?
I was going to ask why the motors would disengage at 25mph because that would be a problem. Had to think about that a few. Ah, so they're engaged to drive all axles from a stop and then automatically disengage the unneeded axles once the trucks hits 25? That would be a nice feature if I'm assuming the function correctly.
Dude, you went down this path already. KISS, normal axles and a normal transfer case. The mil stuff you intend to use is overbuild enough that you won't be saving any maintenance by doing hydraulic or electric.
arse_sidewards said:
Dude, you went down this path already. KISS, normal axles and a normal transfer case. The mil stuff you intend to use is overbuild enough that you won't be saving any maintenance by doing hydraulic or electric.
I know. Several pages of this already. I'd rather go electric, but the cost keeps it out of the question. Never researched much of the hydro option because I didn't feel it would hold up to the constant high speed.
It'll either be AT ISAS or Oshkosh TAK-4. Just depends on what pops up on auction next.
The mil t-case specs aren't being so cooperative. Gears ratios, weight, and center differentials. I've been cataloging and calculating these for the past few weeks. Mess of ratios, I tell ya. And then waiting for the right units to show up on auction. Little by little. Axles first, then whatever drives them.
I look up a huge bus conversion, and YT shoves ALL the overlander conversions at me. There's a few reasons why I didn't want to convert a HEMTT. Cool to see it done, though. https://youtu.be/fCflS7HvVCE
roundhouse said:
Never seen how the tags work
Can’t , unless the bus is up on a lift
I can get good pics tomorrow. I'll be home all day and the bus is already on 20 ton bottle jacks with all wheels off. The tag setup is nothing special. Just there to help hold up the rear.
They're just big swing arms. The tube that spans between each side has bronze bushings in the ends. The arms are held on with clamshells that also have bronze bushing. The spindles are welded the end of the arms. If you were to unbolt the air bags and shocks, the arms would be free to swing all the way around as they spin freely in the bronze bushings. That's about all there is to them. I don't know what they're rated and each side is independent of the other.
JNHEscher said:
Expense. Find me another with TAK-4's for that price and it'll happen. 8x8 starting bids have been around $30k for the last year that I've been looking.
We were all set to buy the firetruck. Even had my route picked out. Found out that the Timoney suspension on it uses an early AxleTech planetary hub that was highly prone to cracking, hence the 30mph speed limit sticker on the dash. We skipped bidding on an AxleTech 4500 in California to wait out on the firetruck. Ditched the firetruck due to the hub issue and lack of support. Two more AxleTech 4500's were up for auction and we couldn't bid because of everything going on with the virus and the fact that we couldn't register the F350 we just bought. Moments after I got insurance on the F350, I got a call from PurpleWave saying that the winner bidder of the Isuzu was not paying and that we could have it for $3200 - right after we paid $5k for the Ford. All good. We got a four door with good power and a stout rear.
That's only about half of it, but covers it well. I'm dead set on putting independent suspension drive axles on. Definitely if we could find a complete, running vehicle that isn't on the other side of the country and within out budget. So far, the axle units themselves are by far the cheaper option and driveshaft sections sell for dirt cheap.
Fun fact: That Timoney suspension is very similar to the Axletech suspension on a Maxxpro DXM
and now I'm thinking you should build a trailer outta that once you do the 24 wheel drive conversion
could have a deck that lays just about right down flat, be real nice for moving milling machines and lathes and shit
[486] said:
and now I'm thinking you should build a trailer outta that once you do the 24 wheel drive conversion
could have a deck that lays just about right down flat, be real nice for moving milling machines and lathes and shit
Don't get me started. I've already be eyeing the tag and steer parts for a beefcake trailer. Alas, I'm supposed to be selling all the factory axle stuff off in order to recoup some of the money that we spend on military drive axles.
[486] said:
and now I'm thinking you should build a trailer outta that once you do the 24 wheel drive conversion
could have a deck that lays just about right down flat, be real nice for moving milling machines and lathes and shit
I’ve seen the rear suspension on the GMC motorhomes
And always thought it would make a nice trailer
