Gearbox problem again...

[Charlynsane]

Hello Guys

On my fully rebuilt engine with the following species

-1293
-22G1128 gearbox
-S/C ST gearbox from MS
-Guess works baulking
-KAD flywheel
-MED S/C drop gear

Everything run smooth BUT!!

When I downshift from 2nd to 1st gear it's scratching a little bit

Of course we check everything during the rebuild process, clearance is good for the drop gear etc..

[LarryLebel]

Synchro worn out, . Double clutch on the downshift.

[Charlynsane]

I just covered 100 miles..

And when I engage the 1st gear, it's fine, only downshift

[Andrew1967]

Did you check the gap between the gear and baulk ring when the baulk ring had ‘locked’ onto the gear ?

[Charlynsane]

I will ask to the engine builder, but it's a very skillful guy

[Lakeland997]

Sounds like clutch drag.
Does it shift well from 2nd to 1st when the engine is not running?

[Charlynsane]

Yes, perfectly

For example, when you stop at the red light in 2nd gear, you can easily engage the first gear

If you engage the 1st gear from the neutral perfect as well, that's why I don't think the baulk ring is worn, not after 200 miles

[Andrew1967]

If you are saying it crunches whilst slowing down and changing down from 2nd into 1st rather than being stationary (stopped) on the road and then going into 1st from 2nd or neutral, that sounds to me that the baulk ring isn’t slowing 1st gear down sufficiently to allow the smooth meshing of the gears.

That to me seems either a baulk ring or 1st gear synchro face issue.

[Charlynsane]

If you are saying it crunches whilst slowing down and changing down from 2nd into 1st rather than being stationary (stopped) on the road and then going into 1st from 2nd or neutral, that sounds to me that the baulk ring isn’t slowing 1st gear down sufficiently to allow the smooth meshing of the gears.

That to me seems either a baulk ring or 1st gear synchro face issue.

This is exactly that Andrew

Any chance that it goes better after a few more miles? baulk ring just covered 200 miles, this the the Japanese guessworks baulking, so as for me the best on the market at the moment

should I wait before to pull the engine out?

[Jason]

I agree with Andrew, it is crunching because first gear is not rotating slowly enough for the dog teeth on first gear to engage smoothly into the dog teeth on the first gear side of the synchroniser hub. Either the baulk ring or worn cone material on the first gear or a combination of both.

[Andrew1967]

I’m not sure it will improve with use but will stand corrected if it might.

Jason ?

[Jason]

I am sorry to say but the mainshaft needs to come out so that the first gear hub and baulk ring can be inspected and tolerance checked. I aim for 40thou gap when the ring grips the gear cone.

[Andrew1967]

That was my thoughts too Jason

[Jason]

Annoying to have to do especially just after a rebuild, but now way round it unfortunately.

[Charlynsane]

Thank you guys

I talk with the engine builder,

We decided to wait a little bit,

As for him, the 1st baulk ring is a little bit tight.. wait and see..

[LuisM]

As for him, the 1st baulk ring is a little bit tight.. wait and see..

Well… I’ve seen similar issue before , with the baulkring sitting so high in the gear cone leading to premature wear of both the ring and cone in less than 200kms !
And then the gear shift started to crunch ( it was on 2md gear though )

Cheers
Luís