Transmission inspection

[markrob]

I think I'm over my head and drowning...I've got my WLA transmission all torn down, but now I'm struggling on determining what needs to be replaced/rebuilt.

From the manual (TM 9-1879) I can see the tolerances on some of the shafts/bushings, (countershaft bushing, side cover needle roller race,etc.), but I'm hoping I'm overlooking a table somewhere that lists all the tolerances on the different race/bushing surfaces in the trans. I'm using digital calipers, but I'm struggling to get accurate measurements to determine whether to order oversize bearings or standard bearings. I'm also having a hard time figuring out how to measure races/bushings that are unreachable by the calipers (in the gearcase). Professional mechanic friends haven't been a great source on advice, since they are all pretty used to the modern world of sealed bearings, etc.

If I can get this figured out, then I'd appreciate any advice on how to best remove any of the bushings that need to be replaced, and then how best to press in the new ones (I've got a small arbor press, and a bigger drill press that I can use when I need more clearance). I've seen writeups about getting custom mandrels made. Most of the surfaces do not seem too worn, although there is some slight pitting on a couple.

Last thing, I'd appreciate any thoughts on "badly rounded" engaging dogs and slots. My worst surfaces are between the shifter clutch gear for second and high, and the clutch gear. There is some rounding, with a small burr edge. I'm not sure if it is reasonable to dress up the edges and go, or if this is a definite call for replacement.

Sorry for the long append, any help is appreciated!

[Paps]

Friend..........you need to allow a reputable builder to look your tranny over. I understand your want in doing it yourseff, but sometimes you find nothing but agrevation when trying to inspect it. I tip my hat to you for trying..........If you need some assistance in rebuilding your tranny, shoot me a personal email, I will help you step by step. Note!!!! When I say you need a part ????? Buy it !!! Don't care where you obtain it but I do care whether it is a good one or bad one. Paps

[Ohio-Rider]

Dial calipers are a great tools for referance fits. There are several tolerances inside your tranny that will required them to be within a half thousands fit. Nobody can do that with dial calipers.

Most shops that do that type of work perfer you bring them the tranny in one piece. They frown on someone bringing in a basket full of parts.

I'm not attempting to discourage you from rebuilding it yourself but its very likely you will need access to a lathe and or a small milling machine at some point of doing the rebuild. If you decide to give it a try there are alot of folks here that can give you good advise.

I'm curious what is wrong with the tranny that makes you believe it needs rebuilding? A few rounded corners in there wouldn't bother me a bit as long as the side clearances where ok.

[markrob]

Thanks for the good info. Kind of a blend between Paps' and Ohio-Rider's appends is where I'm at. I got the bike awhile ago from Steve at Resurrection Cycle. Got it running, rode it once. Next step was to tear it down far enough to get it running better.

Transmission issue was that it wouldn't engage into first, but could be several things since a home-grown foot shift linkage could have caused some of the problem. I'm torn between just cleaning it up and putting it back together, or totally rebuilding the transmission at this point. I was hoping that checking the tolerances would help me make that decision.

Based on Paps' thoughts, I'm thinking maybe I can get the case/shafts checked out by someone to at least determine if the bushings/shafts are too worn, and if I would be better off with some new bushings and/or oversized bearings.

This is a long term project (don't plan on having it done until the kids are older...), so I'm in no big hurry. I'm thinking about picking up a set of telescoping gauges and a micrometer, which might help me make more accurate measurements on the hard-to-reach stuff.

I'm also into any advice about what parts to definitely change out. My wife is pretty understanding, so I'm cleared to buy whatever is needed.

Paps - appreciate your offer on helping on private email, but not sure how I get that from your forum listing.

I really appreciate the help.

[Paps]

You are quite welcome. Email me direct at:
[ vtwinrebuild@yahoo.com ] Note 45 trannies in the subject line so I don't delete it as spam. 45" trannies are tedious builds. Fun...but tedious. Fitting them means several assemblying and disasemblying procedures. The heart of a 45" tranny is the mainshaft endplay. From there, all fitting is done. Since you have plenty of time, I recommend a full inspection of all the tranny components. This means a full disassembly and inspection of all parts. I do not recommend purchasing parts that may not be necessary. One can not determine which parts are worn without a full inspection. I believe you ask which parts are most likely at fault. There is not positve answer for this. It all depends on how the tranny was used or if it was abused over its life span. Most 45" trannies I have dealt with wore evenly all over. They did not need every component replaced. The majority of the internals were salvagable. Paps