OK Tranny guys, need your help...

Discuss fixes, upgrades and modifications to your M37

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Cal_Gary
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OK Tranny guys, need your help...

Post by Cal_Gary »

I finally got to the tranny on Saturday, starting with pulling the clutch access cover, hoping against hope that perhaps something was rubbing down there-no go. So I pulled the PIA floorboard once again (oh well, I need to drill out a couple of the broken bolts anyway and tack a couple of well nuts in). Next I pulled the top cover for inspection purposes. Everything in the cover looked ok but I then spotted the first sign of trouble, so I pulled the entire transmission in order to get into it (again-more practice :cry: ). I have attached the exploded view of the synchronized transmission (scroll down) from the VPW web site so you can follow along:

http://www.vintagepowerwagons.com/pdf/p ... ission.pdf

Parts N thru R have at least 1/4 inch of slop that I can move around by hand, and the pins within part P seem very loose;
Part B which is the big gear up top and at the back, moves easily along the
shaft, but Part D the shim appears to be missing, and when I rotate the gear pack I only get the grinding sound when the Part B gear is moved full forward. I should also mention that before I pulled the tranny I took a lap in 1st gear only with no grinding at all, but it did grind when moving in 2nd and 3rd gear. Could this missing shim be the entire cause of my misery?

I have a complete gear set from AB Linn that I can drop in; however I will also call John B and some other vendors today to price another transmission. Any and all thoughts and guidance is most appreciated, as always-feel free to post-I need your help.
Thanks in advance,
Gary
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1954 M37 W/W
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hbb
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Post by hbb »

Gary what kind of noises were you hearing? What it appliers that you are seeing the play in is the synchronizer set for third and fourth gears! I assume that you are reaching these gears through the shift tower and that they mate up to the shift forks. This slop in the gear set can be caused by the main shaft input bearing being worn or not shimmed properly which could also cause the rubbing noise you were hearing. Was the oil milky metallic looking and if so what metallic color(gold is synchronizer metal and silver is usually a roller bearing failing. at any way the trans should be torn down for inspection so you will have a better idea of what may be going on in it..Oh quick question would the noise change when the clutch was pushed in and did you check the throw out bearing for wear and how it sounds when you spin it that can be another noise source
The wiseman who listens to his students stays a wise MAN!
Cal_Gary
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Post by Cal_Gary »

Thanks HB! The entiure clutch set is new; no discoloration in the oil. I lucked out and found a rebuilt transmission in my home state at a decent price, so I took the plunge and have purchased another tranny.
Gary
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1954 M37 W/W
MVPA Correspondent #28500
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MSeriesRebuild
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Post by MSeriesRebuild »

Based on your description, most likely the later stages of the front mainshaft snap ring syndrone are in play. The early trans you have is notirious for this. you better pull the one you bought down & check for this very prevelant issue before installing it. There is a good chance this issue is present in that one too.
Charles Talbert
www.mseriesrebuild.com
Cal_Gary
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Post by Cal_Gary »

Good advice, Charles, I will do that-thanks!
Gary
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1954 M37 W/W
MVPA Correspondent #28500
G741.org Forum member since 2004
Cal_Gary
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Post by Cal_Gary »

Well I made the trip down south to Antelope Valley Truck Parts over the 4th of July weekend, and Norman really hooked me up! I hauled back a rebuilt transmission, a pristine replacement hood, pristine driver's front fender, t/o seat bucket and the like. To top it all off, Norman made a special trip to open his shop just for us, as they were closed for the long weekend-glad I took my parts getter S-10 instead of my wife's SUV!

Many thanks to Norman if you're out there-your kindness is much appreciated!
Gary
Cal_Gary
1954 M37 W/W
MVPA Correspondent #28500
G741.org Forum member since 2004
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