TZR Forum

TZR Specific => 1KT 2MA 2XT 3XC (R1Z) etc Range => Topic started by: saltysealion on April 15, 2018, 12:45:46 PM

Title: Transmission bearing replacement
Post by: saltysealion on April 15, 2018, 12:45:46 PM
Hi,

Attempting to replace the bearing on the transmission


Its the shorter stack.

It seems that the bearing is pressed in from the left as there are gears on the right side of it.


Has anyone here replaced it? Any tips?

Ive tried using a bearing puller but its such a tight fit

Banged it using wood to hold around the bearing but have only managed to make the bearing more noisy.

I can see the outer race starting to be torn off but the inner stands still

Help!
Title: Re: Transmission bearing replacement
Post by: Toop on April 15, 2018, 03:54:27 PM
Heat the inner ring for disassembly and to reassemble the new.

it is sometimes difficult for disassembly, but since the bearing is dead I cut it to leave only the inner ring that falls alone when it is sufficiently heated  ;)
Title: Re: Transmission bearing replacement
Post by: saltysealion on April 15, 2018, 06:59:16 PM
I managed to pull it off. The bearing puller was stressed to its limits but managed to hold together.

Do I just heat the inner race to press it in?

I noticed at the end of the rod, there is a cap I pushed it in and got it out... planning on using some gasket to glue it back on the end, I looks like its job is to stop the oil and make it come out of the bleed holes, is it critical that it seals? I dont see any o rings or anything.

Title: Re: Transmission bearing replacement
Post by: Mick on April 15, 2018, 10:11:44 PM
Put the shaft in the freezer for a good hr and then put the bearing in the oven for 15min at 100-150c(not sure what that is in F).It'll just slip on.
Title: Re: Transmission bearing replacement
Post by: Toop on April 16, 2018, 09:22:32 AM
130-160 Celsius

130 if the shaft in the freezer (one night)
more than 160-170 if not freez the shaft
Title: Re: Transmission bearing replacement
Post by: saltysealion on April 20, 2018, 03:11:50 AM
My oven is shot so I can't accurately set the temp... also makes cooking hard :)

What temp am I aiming for in terms of the bearing itself, I can shoot it with a heat sensor
Title: Re: Transmission bearing replacement
Post by: saltysealion on April 21, 2018, 01:57:15 PM
This is informative: http://www.ntnglobal.com/en/products/instruction/mounting/index.html

So I cooled the rod down to -10c and the rod to 100c.

It didn't go so well, before the interference part, it already snagged on something. Perhaps the hot/cool was conflicting?

I used a hammer and the old bearing with a pipe to tap it into the tight part. It didn't take much force but not something that can be applied by fingers.

From here, I just pressed it together using a threading rod.

I now have a new bearing on the shaft. I can't say I'm very very impressed with the near bearing, it doesn't spin PERFECTLY smooth but it is much better than the old one.

Pictures to follow.....
Title: Re: Transmission bearing replacement
Post by: saltysealion on April 21, 2018, 05:20:13 PM
Pictures of the presss and end result
Title: Re: Transmission bearing replacement
Post by: saltysealion on April 23, 2018, 08:24:55 AM
One of the biggest difference is a shim I installed as part of the reassembly

There was a 0.5mm diffference between the new and the old. Could that be from wear and tear?