Rebuilding the GP100

**Henk** · 14th August 2009, 22:34

They should turn freely. It's not in gear is it? Should still turn OK even if it is I think.

**Slingshot** · 14th August 2009, 22:38

Originally Posted by Henk

They should turn freely. It's not in gear is it? Should still turn OK even if it is I think.

Tried turning in gear and in neutral, doesn't seem to make any difference.

**Henk** · 14th August 2009, 22:50

Do the shafts turn at all? Been a while since I've had anything that far apart but from memory you should be able to turn either shaft and with some effort both of them with the box in gear.

**Skunk** · 15th August 2009, 00:53

With my TF I had to hit it with a soft face hammer on the end of the shaft. Turned freely after that. Next time I had to the same thing.
Funny cos with the AX I never needed to.

**Trudes** · 15th August 2009, 08:01

The MB did the same thing... I think Sully may have used a similar method to Skunk's.....(Give it the bash)

**bucketracer** · 15th August 2009, 09:38

With my GP100 I had the same problem, To find what was wrong I assembled the cases with one shaft at a time to find which one was binding. Each shaft should have some end float, 0.25-0.5mm. Turned out I hadn't seated one of the bearings properly.

Other problems I have heard of was a selector draging on the bottom of the grove in the gear (could happen with a mix and match gearbox from different years I suppose) and the small washer on the end of the output shaft was to thick.

**Sketchy_Racer** · 15th August 2009, 12:53

Give the shafts a medium whack on the end of them to seat the bearings in. When you bolt the cases together the interference fit of the bearings mean that there is still a large amount of side load on the bearing, causing the stick that you are getting. They just need a whack to push the bearings fully into their seats and you'll be away laughing.

**Slingshot** · 15th August 2009, 16:44

Good advice

A couple of gentle taps and she's turning nice and freely

**F5 Dave** · 16th August 2009, 10:38

Yeah they usually make a nice creak/crack noise.

**speedpro** · 16th August 2009, 13:04

That'll be your collarbone you are listening to.

**Slingshot** · 17th August 2009, 21:52

I'm now putting the rotary valve assembly back on so I need to decide if I'm going to open up the disk...problem is that you only get one shot at these things.

I'm thinking I might go half way between the GP100 & GP125 opening...surely that would be OK.

**quallman1234** · 17th August 2009, 22:26

Originally Posted by Slingshot

I've got a few questions about putting my GP100 motor back together, the first one is rhetorical.

- Why did I think it was a good idea to fix something that wasn't broken.
- Should I put some locking compound on the outside of the bearings to keep them from spinning in the housing...or is this not necessary?
- I've got a new gasket set..the question is should I use a gasket between the crank case halves? And should I use goopy stuff to make the seal better?

I'm sure I'll have more questions, but answers to the above would be handy to start with.

Cheers John

10 Characters.

But a little bit of a grind can't hurt if you know what your doing.