Transmission Overhaul

[OZM29C]

When I rebuilt my weasel T84 transmission I incorporated a few modifications that I hope will help to extend the life of this transmission. I fitted high capacity bearings front and rear. I substituted the pilot rollers between the main drive gear and the main shaft with a bronze floating bush. I fitted an oil seal to the front bearing retainer cap in lieu of the cork seal and then fitted viton o rings retained by nylon collars to the selector shafts. I posted previously about using a generic metric seal for the transmission output shaft. I was unable to source a weasel cluster gear so I have fitted a standard MB/GPW Jeep cluster gear. I machined a thicker thrust washer to compensate for the difference in the overall length between the two cluster gears. The Weasel cluster gear is the longer of the two. I also fitted new synchro blocking rings and a selector shaft detent ball assembly. The true test of my work will come later this year. Cheers. JW

[Jesse Browning]

Nice work. I found when I rebuilt my T-90 back in 2013 that there were several rock crawler companies that had single parts to entire transmissions for sale. 

[Jim Gilmore]

John,

There is a modification publication that shows how to use the MB/GPW cluster gear in the Weasel T-84. I'll dig it out of my files......but I think you used two of the jeep trans spacers to use that cluster. I'll post it when I find what box it's in......

And......don't forget to use that 90 degree pipe elbow on the filler neck to raise the fluid level in the trans.........very important to use it.

Jim Gilmore

[BCA]

Great to have a new Weasel forum. I am dissecting an NOS T84 Weasel transmission and very interested to see JW's comment on the length of the cluster gear: I had over-looked that. Also my transmission has a 25 tooth low & reverse gear (the G503 t/m uses a 25 tooth gear) despite the Weasel ORD9 specifying a 24 tooth low & reverse gear. Is this a mistake in the Weasel parts book?  Any other comments on the interchange between G179 and G503 T84 transmissions?    …… Brian

Edited April 14, 2020 by BCA
spelling

[Patrick Tipton]

Nicely done John.  I am looking forward to working on my running gear later this year.

Patrick

[Jim Gilmore]

Brian,

How do you know this is a Weasel transmission?

This transmission was also used in other vehicles and cars.

Might be for one of them?

[M29C3284]

The 1944 edition of ORD 9 specifies a 24 tooth gear but in the 1953 edition, the one from Portrayal press, the 24 has been crossed out and 25 entered instead. This gear, 197376, is also used in the 1939 and 1940 Studebaker Champion cars, but in the parts catalog for those the tooth count is not mentioned. So I checked one of the two T84J's I have, and it also has a 25 tooth low and reverse gear. It is not NOS so the gear could have been changed. I also have a NOS/very lightly used T84J, that had never been taken apart before I restored it, that I can also check but unfortunately I can't get to it right now.

From comparing the G503 and the G179 transmissions I have found that at least these parts are interchangeable:

194264 - Thrust washer

903406 - Thrust washer

903407 - Thrust washer

513002 - Countershaft

513003 - Plate

900889 - Cluster gear bushing

512990 - Roller

512998 - Shaft reverse idler gear

903405 - Reverse idler gear

900899 - Synchronizer assembly

 

 

[BCA]

Jim: I’m pretty confident that my transmission is for Weasel: olive green, has all the G179 features. At this point, given that all the ratios are the same for G503 and G179 transmissions, I am assuming that both use a 25 tooth low & reverse gear. M29C3284: Thanks for the interchange list and the mention of the notation  (correction?) in the later ORD 9.There are small changes in the gear numbers that make it difficult to prove G503/G179 interchangeability by part number but some of the number changes are just upgrades or production modifications to an otherwise interchangeable part.   ...... Brian

[Jim Gilmore]

I have a WW II ORD document that goes over the interchange GPW transmission parts to Weasel.

On of the things it covers is using a GPW cluster gear in the Weasel trans. Additional spaces/thrust washers were needed.

I will see if I can find it in my computer and post it here.

[Juliet Golf]

Realize this is an old thread but there may time to go back to the job before running or help others.

Nice work BUT one important thing I notice as apparently missed & that is that the fabricated brass/bronze rear thrust [pictures 3 & 4] looks like it can turn on both the case & the counter gear face.

Now this is very problematic. Any & all thrusts must only work on the machined gear faces & never turn on the housing, but be tabbed to or pinned to the gearbox housing.

The thrusts are wearparts/sacrificial BUT gearbox housing is NOT.

[OZM29C]

16 minutes ago, Juliet Golf said:

Realize this is an old thread but there may time to go back to the job before running or help others.

Nice work BUT one important thing I notice as apparently missed & that is that the fabricated brass/bronze rear thrust [pictures 3 & 4] looks like it can turn on both the case & the counter gear face.

Now this is very problematic. Any & all thrusts must only work on the machined gear faces & never turn on the housing, but be tabbed to or pinned to the gearbox housing.

The thrusts are wearparts/sacrificial BUT gearbox housing is NOT.

Thanks @Juliet Golffor your close scrutiny of the small thrust washer. What's not shown in the photos is that I have indeed drilled a tiny locating hole in the opposite thrust face to engage the tiny transmission housing dowel pin. Rest assured, the thrust washer does not rotate.

BTW welcome to the Weasel forum and do share your weasel story with us.

Edited December 9, 2024 by OZM29C
remove repeated word

[OZM29C]

The other item of note from my previous post was that the substitution of the main drive shaft to main drive gear pilot rollers with a bronze bushing. This modification turned out to be an absolute disaster. What I tried to accomplish was an easy fix to compensate for the main drive shaft spigot that had been machined under size (???? for reasons unknown). See photo. In view that replacing the main drive shaft was cost prohibitive I press fitted an inner metric bearing race IRT1216 and that repair seems to be holding up to date. See photo #2

 

 

[Jesse Browning]

These transmissions seem to be a favorite for the “rock crawler” crowd. Some of the suppliers have any and all parts for them, including whole new transmissions.

[Jim Gilmore]

As a follow up from my previous comments.

When using a GPW #7113 cluster gear in a Weasel transmission you should use one each of GPW #7126 and #7129A rear countershaft thrust washers.

The Ordnance Dept recommended using GPW parts for this.

[Juliet Golf]

17 hours ago, OZM29C said:

The other item of note from my previous post was that the substitution of the main drive shaft to main drive gear pilot rollers with a bronze bushing. This modification turned out to be an absolute disaster. What I tried to accomplish was an easy fix to compensate for the main drive shaft spigot that had been machined under size (???? for reasons unknown). See photo. In view that replacing the main drive shaft was cost prohibitive I press fitted an inner metric bearing race IRT1216 and that repair seems to be holding up to date. See photo #2

 

 

I did observe that & it is good to know what did work for you. My observation @ the time would have been that had the nose [pictured] if the mainshaft was re-hardened the modification would have probably worked fine, but seems your ingenuity saved the day. Good job. JG.

Edited December 9, 2024 by Juliet Golf