Ok, I have done many transmission repairs, so I'm not a total idiot. Ok, heres the problem. I had to replace a mainshaft in a type r. So now I'm trying to get the mainshaft thrust clearances right. I have a factory sevice manual, and its just vauge as hell as how to do this. It says insert the mainshaft into the gear housing with bearing attached without 72mm shim, and place the flat washer that goes on the clutch housing side of the shaft. Use a straight edge and measure the distance between the washer, and the end of the face of the gear housing. (I'll post pics tonight to avoid confusion) Ok, I understand that part... but, then it says to measure the distance between the rear of the bearing in the gear housing and the end of the gear housing. I tried doing that, and used the formula in the manual to find the proper 72 mm shim. But, the one i need is way too small and is not listed in the book. I think I'm doing something wrong. I tried using a veneer caliper and a height guage. What I did was measure the thickness of the inner race of the bearing and measured the total distance from the top of the inner race to the gear housing. Then subtracted the thickness of the inner race from the total distance to come up with the clearance between the back side of the race and the gear housing. WTF is that right?

I figure I could just put it together without a shim, and then measure the end play clearance with a dial indicator. Then figure out what shim to use. I really dont want to open it up and close it like 50 times, but if I have to, I will. I have replaced every bearing / seal in this thing, along with most of the syncros. I have to get this clearance right.

I hope this is not confusing. I'll try to post pics tonight.
sorry for the big pics


the bearing is not seated all the way down in this pic. Just for reference.


Thanks T


Modified by ludedeg at 9:04 PM 12/20/2004


Modified by ludedeg at 9:16 PM 12/20/2004

 

Are you measuring at the backside of the bearing and housing or are you measuring from the seal side of the bearing and housing (not that I think you could do that, but hey, anythings possible I guess).

Are you subtracting .93 from your sum of the two measurements, or possibly miscalculated?

Not trying to offend, but mistakes happen...

let me know if there's anything else I can do or PM me and I'll try to answer your questions as best I can.

 

PM's replied. Thanks

 

You really have to read the shop manual clearly. The cheesy diagram
doesn't make it obvious. You need to measure the gap between the
case and the mainshaft bearing (installed in the case -- NOT the bearing
above the 5th gear)

Here's a picture. Yellow marks show where the measurement is taken.

 

ahhhh finally a picture that describes it!!!

the Helms diagram is not very clear

thank you so very much!