Tranny dilemma

I have already completed my dana 18 rebuild, and started in on the T86 today. Thats where the problems started. My countershaft gear set is unusable, and the reverse idler gear is trashed too ($170 to replace both). I already have a T86 rebuild kit from Herm ($110). ($280 total)

I have a T90 with Buick V6 adapter/input shaft sitting on the garage floor that is from my parts JEEP. It collected water and the gears have substantial surface rust in spots. I don't really know how usable they are, maybe a blasting and they would be fine? The gears are not chipped/excessively worn. I would have to buy a T90 rebuild kit. I have a big hole dana 18, but I read I can put the T-86 bearing retainer on the back of a T-90 and and use my large hole transfer case.

At this point, I don't know whether I would be better off to buy one of Herm's rebuilt T86's (or T90 with long shaft and adapter, ($275-300, plus shipping), or try to use the T90 I have on the floor. Unless someone has a spare countershaft gear set laying around for less than $140, I don't see using my T86 as an option, and will return the rebuild kit.

Any opinions?

 

would go for the t-90 or even the t-14.

 

As long as you're going to spend a bunch of money, why not put in a T18? They're getting cheaper now that a lot of us are taking them out and going with automatics.

 

I would also go the T90; parts are plentiful and inexpensive, compared to other models
I would rebuild what you have; then you know what's inside.
if the teeth aren't severly pitted, may be okay, just noisey; got pics ?
if you only drive the Jeep say 5000 miles or less a year, may not be a problem at all
I have not been impressed with some recent "rebuilt" transmissions I have seen.

 

Hers is a pic. not sure if it will tell you too little/too much

 

hard to say from that pic; the rust wil clean off
bead blast 'em and then see what you got
minor pitting is no biggy
teeth missing/severly gaulded, that is different

 

Forgot to mention. The cluster gear and reverse idler are in perfect shape, as they were completely submerged in gear oil. Only the top 1/3 of the teeth on the main shaft gears have surface rust, what was above the oil level.

 

I could show you a good pic from the T86 cluster gear of severe chunks and half missing teeth. It's weird, it seems like these T90 gears have no wear at all. I think it may have been rebuilt shortly before or while the JEEP was parked and left to rot (by the guy I bought it from). The other strange thing is the only spec of rust on that jeep is IN this transmission.

 

I can PM my addy if your dad wants to pull it apart and send me the reverse idler and cluster... Back to reality.

 

Regarding rust removal, can I do that myself, or should I take them to a machine shop? I might have access to acid if need be (hydrochloric, sulfuric, acetic, phosphoric), but have no idea how strong, how long to dip them.

 

Mike do not use acid to clean these parts.
This is the preferred method and it does absolutely no damage to the part, i have several friends that have used this and have seen several old machines done this way and they came out awesome looking.
http://antique-engines.com/electrol.asp

 

Mike, maybe you should wait for Nick to weigh in on this. I thought that you could take T-90 internals and install them in a T-86 case... re the T-86 parts, if you talk to Herm, I'd expect he'd help you out with exchanging the parts. I'd also expect that the T-86 will share a lot of small parts with the T-90, so you may not need very many new/different parts.

I've no experience with the pre T-14 Borg-Warners, but if I had this collection of parts, I'd try to use the case, adapter and input shaft from the T-86, then use the T-90 countershaft, gears and main shaft. As I understand it, the T-90 and T-86 are the same internally except for the spiral splines on the main shaft, and the first/reverse is beveled instead of straight cut. You'd even have the T-90 adapter and mainshaft left over, which tou could sell. Should/might be do-able.

 

I am going to start my science fair project for rust removal to see where I stand. I think putting T90 internals in my case looks like a good option right now if my T90 gears are in good shape. Otherwise, it looks like I will be able to get another T86 for parts to replace mine at reasonable price.

 

Good job, you jumped right in with both feet!