NOS Cluster Gear Inspection Help

[Daves43GPW]

Hello All,

I was able to get my donor T90 torn apart last weekend and started inspecting all of the parts. I noticed the cluster gear ID had visible wear where the needles bearings ride so I decided to replace it. I purchased an NOS Lempco gear on Ebay which came today. I noticed there are two major differences between this gear and the gear I pulled out of the transmission. The front bearing surfaces on the NOS gear looks thinner and the rear "tabs" that support the rear thrust washer are significantly larger as shown in the attached pictures.

What are everyone's thoughts, Are these differences going to have an impact on performance or am I getting worked up over nothing?

Thanks,

David 

[athawk11]

This is a tough call.  My biggest concern is the thicker surface on the big gear side.  None of the photos of my stuff show this surface.  Could this NOS gear represent an �improved� later version of the cluster?

I would probably assemble the transmission, check tolerances, gear mesh, etc and see how it fits.  Although, I�m not much of a gambler.  For me, it seems like the house always wins. 

[Austin]

Don't chance it if the part you are changing is obviously different. I used a replacement oil pump on my L134 rebuild that completely destroyed my cam right after I got everything back together. Needless to say I had to take the engine apart and invest more time and money. To the eye, the new and old pump were identical, but the shaft on the new one was 1/8" longer.

I would hate for one of those teeh to break off or something to bind and do farther damage to your transmission .

[Tumbleweed]

I'm with Tim on this........prior to doing assembly I would measure your new cluster gear to see if there is a considerable mount of difference compared to your old gear. I would assemble the cluster gear and see how tight it is and if it turns easy enough assemble the rest of the gears and check end play, mesh, etc.

Anyone who has done a transmission rebuild can tell you you will always do it more than once!

[Daves43GPW]

I would like to thank everybody for their inputs on this issue.

I don't have a pair of calipers or micrometers large enough that can measure the length of the gear, but putting the new and old gear side by side on my workbench it looks like the new gear is a few thousands shorter then old. Reading te service manual I believe the proper end play of the installed cluster gear is 0.012-0.018" so there is a risk this new gear will not meet his spec. I guess this will just have to be something that I'll have to check during installation like Tim and Tumbleweed recommend.

Any concerns with the larger machined tabs on the small end? Assuming the end play is still within the factory spec does anybody think there is risk with having a thrust washer that might have a little "back and forth slack"?

Thanks,

David

[SPM1US]

You might try reaching out to Herm Tilford - Herm the Overdrive Guy - he has built thousands of these transmissions and would be able to give you a definitive answer as he has used thousands of T90 parts over the years. Herm is very reputable and an excellent source of knowledge and all types of Jeep rebuild parts.