thrust washer?

[ed rex]

Been rebuilding my TH350. B&M Transkit. Thanks JT.

Down to the final steps and have encountered a prob. You're suppose to bolt the oil pump in place and check for end play. The spec is .015 - .030, mine is considerably more. The instructions say 'get a thicker thrust washer from your GM parts dealer to adjust to proper end play'. All the GM parts places I've called say 'huh?' 'A what?'

Anybody know where I can get a thicker washer?

 

[ed rex]

OK, got it figured. The spec on the B&M Transkit for the TH350 is incorrect. According to several tranny shops here, the spec should be between .050 and .100. NOT .015 and .030.

Other than that, the kit has been a cakewalk to install. Step by step instructions that are thorough and accurate. No difficulties encountered thus far with the end play spec being (hopefully) the only exception.

 

[Greg72]

Ed,

You oughta let B&M know about that.....maybe they'll fix the instructions to save the "rest of us" later on. And getting "confirmation" from them that the spec is .050 - .100 would be good "peace of mind" to have.



-Greg72

'72 K5 Blazer - 427BB/TH350/NP205/6" Lift/35x12.50's
<font color=blue>See it here: </font color=blue><a target="_blank" href=http://coloradok5.com/gallery/albun38>http://coloradok5.com/gallery/albun38</a>

 

[Ryan B.]

<blockquote><font class="small">In reply to:</font><hr>

Other than that, the kit has been a cakewalk to install. Step by step instructions that are thorough and accurate. No difficulties encountered thus far

<hr></blockquote>
Now that's what I'm looking to hear. I plan to eventually drop out my TH350 and NP205 and rebuild 'em both myself.
It's encouraging to hear that it has been a "cakewalk".
I see the dudes down at aamco that are rebuilding transmissions, and I think to myself why couldn't i rebuild my own?

[Real Men Don't Care About Gas Mileage Or Rapid Tire Wear!]
1972 K/5
Ryan B.

 

[ZZ4x4]

Ed,
Glad everything is working out! And, yup, I found the same thing with the thrust washer. A local trans shop told me the end play does not need to be as tight as the B&amp;M instructions. Sorry I forgot about that point. Great Job. JT

 

[BARRAZA]

The B&amp;M instructions are not wrong!! Correct front end play is critical to long tranny life. Excess end play can cause rapid oil-seal and bushing wear where the direct clutch drum rides on the front pump cover stator support. The Chevy overhaul manual says .032-.064 when the trans is on the bench but this includes about .020 of normal rear end play(rear end play is not critical). With the trans on end facing up and the output shaft hanging free, force the input shaft down by hand, zero the dial indicator, then push the output shaft up(forward). End play by this method should be in the range B&amp;M specifies or up to .045 max. The thrust washers were available in .066, .083, and .100, a GOOD shop should be able to to get them. They may be confused because the thrust washer was changed to a shim and a torrington type needle bearing about 1975, the thrust washer is considered better for HD applications.
Before you close it up, you should really consider replacing all the bushings. The B&amp;M instruction recommend this but they dont include the parts. Most trans shops dont bother because its extra work and the probability is grandma's buick will be fine without them. As much of a PITA as a trans removal is, take your time and do it right - once.
Excellent book : Turbo Hydra-Matic 350 Handbook from HPBooks by Ron Sessions. Summit used to have it and I have seen it at Barnes and Noble.

 

[ed rex]

Barraza....thanks for the input. However, I'm not sure how the B&amp;M instructions are 'not wrong' when the Chevy overhaul manual say's .032 - .064 and the B&amp;M say's .015 - .030. Certainly if 'rear end' play is a factor, then in the very least the B&amp;M kit is confusing. The way the kit instructions describe the procedure is basically the way you did....with the tranny vertical and the output shaft dangling free....but then simply states to grab the input shaft and tug upwards. This measurement should be between .015" - .030". No mention of rear play. No mention of pushing upwards from the rear or 'bottom' as the criteria as I understand it is to address the input end play. In any event, using this method, I ended up adding 2 shims to tighten the (input shaft) end play to .050, or there abouts. I hear what your saying about the thrust washer but have been unsuccessful in getting a larger one so simply shimmed.

Your response indicated that there are washers available in several sizes with .100 being the thickest. However, the stock washer is about .150. Are you saying that one should add additional washers? If so, what would be the difference between adding additional washers or shimming?

BTW - Button'd the unit up and tried it last Sunday. Works like downtown! I'll create a new post detailing my experience for those that are interested.