The OEM TH400 (475) is a good transmission but mine has 125,000 miles pulling 86Barth and sometimes a trailer. It runs at or near the GVW limit all the time and howls pretty loud. When I get the VW toad ready the trans will be heavily loaded when pulling it.

When I replaced the engine with the 454HO I am pushing the hp and torque limits as well. Stock trans is rated about 400 hp and 450 lb/ft of torque. The 454 HO is good for over 400 HP and over 500 lb/ft torque.

After some research I ordered a rebuilt trans and new torque convertor from TCI Auto. Trans is designed for towing/motor home. Rated for 500 hp and 800 lb/ft torque. The torque convertor is the special HD version with brazed fins, etc. It has low stall and 4% tighter "lockup" when at speed.







Now if I could just get it to "jump up" into the coach!

That will leave only the rear axle gears left to finish the driveline. (I aready replaced the outboard bearings, seals and rotors)

Have Barth, will travel

When you finish put the 400 on CL. Dirt track racers pay $750 wo converter for those.

quote:

Originally posted by Tom and Julie:
When you finish put the 400 on CL. Dirt track racers pay $750 wo converter for those.

Cool!
I didn't know they were worth that much. (Don't tell Liz I'll say I sold it for $50)

I will start removing the old one soon, prob tomorrow.

Steve , I was looking on TCI's website & I know you already have a trans cooler .

But, did you get the th400 rv & towing transmission package or just the trans & new converter ? Look's like a very good package .

Bob

I got the transmission and torque converter only. As you said I already have a good cooler system.

Hopefully, they should be good for the job. I want to get it done soon so it is ready before the Allegan GTG.

to be continued:

Steve , I was thinking of putting in a trans cooler . When replacing my engine with the ho 454 , i left out the air condition condenser . It looks just like a trans cooler .

Do you think i could use the condenser as a trans cooler ? Or is there a difference in them ?

Sorry for the thread drift . Thanks , Bob

I suspect it would be OK… most ACs have pressure at or above the normal cooler line pressure. I would be sure the tubes are large enough to insure adequate flow, especially when first cold and the ATF is thicker.

Check your PMs.

I would be very careful to at least flush the A/C condenser a lot! A/C systems use different oils and if the A/C pump died there is a good chance pump particle residue is in the condenser.

Personally I wouldn't do it and just get a new trans cooler.

One (freon) is a gas in fluid form with very high viscocity - the other (trans fluid) is thick. The trans fluid will never flow through the small tubes in the ac condenser. Suggest getting a real one if you really need it. You are not dealing with an Allison with the pressures and temperatures a diesel produces.

Getting closer to the exchange. I unbolted the front u-joint and the center bearing. I tied the driveshaft off to one side.



I already knew the tail housing on the Barth trans is not the same as the rebuilt one. The vehicles that had the parking brake on the tailpiece are somewhat rare compared to the generic 4 inch housing. The parking brake versions are slightly longer and have a rear flange with four holes to allow mounting of the brake backplate, shoes, etc.

I wanted to see if the old yoke would fit in the new trans. I pulled it out of the old trans. With a bit of cleaning, the 32 spline yoke did indeed fit on the new output shaft, also the center bolt that holds the yoke on the shaft fit the threads in the shaft. so far so good.





Only problem is the standard housing is about 3/4 inch shorter than the brake version. I will have to reuse the old tail housing.



Actually I am not disappointed. It turns out the longer housing has an extra rear ball bearing that helps support the weight of the brake drum and driveshaft. I'll just replace the seal while it is out.

My parking brake has not worked for some time. It was activated by 2 cables that connect the hand brake lever and the brake itself. Long ago the cables rusted solid, someone cut them off and the ends are gone. The cables are long gone out of GM stock.

I will leave the brake parts off for now. Since they didn't work anyway, I haven't lost anything. Meanwhile, I will rebuild the shoes and drum assembly. I will try to get a single long cable custom made to connect handle and brake.

When I get all the parts together, I can just pull the front ujoint and yoke, reinstall the back plate, drum and cable and be done with it.

Lokar makes parking brake cables in a variety of lengths and a little longer is not an issue. Should save you the custom up charges.

I got sidetracked a bit. I removed the tail housing from the Barth trans. It is indeed a heavy duty assembly. The housing is longer and has wider mounting pads. The standard housing had a single sleeve bearing at the yoke end. The HD has two ball bearings inside, apparently to help support the weight of the brake drum and drive shaft attached to the yoke. Both bearings are loose and show signs of rust in the past.

The bearings are labelled NDH L09. My local auto parts guy could not get a match. Research shows this is a New Departure Z993L09 ball bearing. 65 mm OD 45mm ID 16 mm wide. They are no longer made and no common cross references. No luck with Timken, BCA, Detroit Ball, Federal Mogul.

I was able to find 2 NDH Z993L09 on eBay and they should be on their way. I will be ready for the Allegan GTG.

The rear seal is also different but still widely available. OEM # 8655032 (CarQuest/National 2457, KOK 11061)

A few more things to remove from the trans. I will hopefully have it out later today. I will install the new trans sans the tail housing. It can easily be bolted on after I install the bearings and seal.

I will have pics for the next posting.

After a day of needed rain, I am back to the coach.

I removed the brake plate, the rear housing and the cross member. Ready to go, except the cooler lines.



Two jacks, one for the engine, one for the trans.



A few minutes later. I had to jack the coach up about 2 inches to clear the trans. Gone with the old…





In with the new. (At least part way!)



Only one problem noted. The lower right engine bolt is broken off in the block next to the starter, I will have to remove the stump. Not rusted, should be OK.

I cleaned and painted the old tail housing. Bearings will be here Monday morning. In the meantime I will install the new trans, connect everything, reinstall rear cross member. When the bearings arrive on Monday I will install them and the new seal in tail housing, then install housing, driveshaft and ready to go!

I got the new trans in and resting on the crossmember. Now for that other tail housing.



A tale of two tail housings. The TH400 has a 4 inch tail housing with a single sleeve bearing. The TH475 has spur gears and a longer tail housing with the brake drum. This tail housing is much more stout, it has two ball bearings to support the heavy yoke, brake drum and front driveshaft. The bearings arrived today. Quick install and we're ready to go.



Note that the yoke is very heavy, has a flange for the brake drum, and sleeve areas for the two bearings and the seal.



Two torque convertors. The TCI on the right has heavier welds around the center stub, also you can see "blobs" around the shell where the internal fins were brazed/welded.



Got the rear housing bolted on, installed new rear mount, bolted in the cross member. Installed the yoke, then the driveshaft. Also changed the pan back to my old one. It holds about 2 qts more and has a drain/temp gauge. I left the brake parts off for now. If you look in the center of the yoke you see the bolt that holds the yoke on the output shaft.





Tomorrow I will attach the shift linkage, cooler lines and speedo drive. Fill it up and run it!

As always, good work and good tutorial.