Page 1 of 1

6 gear thrust bearing 6627 replacement in 2021

Posted: Tue Aug 10, 2021 7:04 pm
by JosephS
Hello all
Typically I would just e-bay the parts and call it a day, but thrust bearing is expensive enough that I want to learn a bit more.


I'm have 2 gold pan projects one will be very lightly run with a stock motor on 6 cells and the other a Monster truck basher with a 2/3s lipo and a 13t brushed.

How much difference will a worn but functional vs fresh thrust bearing make?

Is there a way to tell how healthy these are without building the transmission all the way up?
Is there a way to 'freshen' it up?

Does anyone have a reasonable source on a 6 gear thrust bearing replacement?

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Tue Aug 10, 2021 9:02 pm
by juicedcoupe
I have an extra one of these laying around.

https://www.fasteddybearings.com/3x8x3-5-thrust-bearing/

I checked it on a spare diff shaft. The caged bearing fit fine but the hardened races that were too small (3mm vs 1/8").

I'm sure that it could be made to work.

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Tue Aug 10, 2021 10:03 pm
by CrazyRC
I don't have an Associated bearing in front of my to measure, but there's this guy from McMaster Carr.

Fits 1/8" shaft, 7/16" OD.

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Tue Aug 10, 2021 10:42 pm
by JosephS
juicedcoupe wrote: Tue Aug 10, 2021 9:02 pm I have an extra one of these laying around.

https://www.fasteddybearings.com/3x8x3-5-thrust-bearing/

I checked it on a spare diff shaft. The caged bearing fit fine but the hardened races that were too small (3mm vs 1/8").

I'm sure that it could be made to work.
Any idea if it's about the same thickness of the original one? Would this need grease?

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Tue Aug 10, 2021 10:52 pm
by juicedcoupe
JosephS wrote: Tue Aug 10, 2021 10:42 pm
juicedcoupe wrote: Tue Aug 10, 2021 9:02 pm I have an extra one of these laying around.

https://www.fasteddybearings.com/3x8x3-5-thrust-bearing/

I checked it on a spare diff shaft. The caged bearing fit fine but the hardened races that were too small (3mm vs 1/8").

I'm sure that it could be made to work.
Any idea if it's about the same thickness of the original one? Would this need grease?
From what I remember, the original one was thicker. A 3mm or 4-40 washer should serve fine as a shim.

I would grease any of them. Even the newer manual for the re-re calls for grease.

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Fri Sep 24, 2021 3:32 pm
by JosephS
CrazyRC wrote: Tue Aug 10, 2021 10:03 pm I don't have an Associated bearing in front of my to measure, but there's this guy from McMaster Carr.

Fits 1/8" shaft, 7/16" OD.
For future folks the McMaster carr part is identical to the associated part
D8CDF602-2266-454F-B54B-1E78CA45401A.jpeg
The dirty one is from the kit and the clean one is the McMaster carr part.

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Fri Sep 24, 2021 4:24 pm
by juicedcoupe
FWIW, I used the smaller Fast Eddy bearing (caged bearing only) on a six gear the other day. I just needed a thin washer as a shim, placed on the teflon bushing side. The shim provided proper spacing and prevented contact between the small bearing and the teflon.

It works and turns smoothly, but I'll likely eventually replace it with a correctly sized bearing.

Re: 6 gear thrust bearing 6627 replacement in 2021

Posted: Sun Sep 26, 2021 9:46 pm
by JosephS
JosephS wrote: Fri Sep 24, 2021 3:32 pm
CrazyRC wrote: Tue Aug 10, 2021 10:03 pm I don't have an Associated bearing in front of my to measure, but there's this guy from McMaster Carr.

Fits 1/8" shaft, 7/16" OD.
For future folks the McMaster carr part is identical to the associated part
D8CDF602-2266-454F-B54B-1E78CA45401A.jpeg

The dirty one is from the kit and the clean one is the McMaster carr part.
I found after my build that I needed the original thrust washer that allowed the teflon from the diff pinion to go through. I am not sure if that was really necessary or if something else was misaligned.