Sierra cosworth 2wd grinds first gear from a full stop

**Andre** · 16-05-2021, 22:15

Hi guys

I've been having an issue ever since I rebuilt my T5.
Changed synchros and stuff but forgot to change the pilot bearing.
And it grinds if I engage first gear from a full stop... I've since changed the pilot bearing but the problem persists...

Can someone help?

Thanks

**alladdin** · 17-05-2021, 11:58

i think they were always hard to engage 1st but not a grind. is reverse the same ? sounds like clutch possibly not fully disengaged

**Colr6** · 17-05-2021, 12:32

To much loading on the main shaft bearings ? That may keep the shaft spinning when it shouldn’t but normally would give hard selections. As above if the same problem persists with reverse then clutch clearance may be an issue.

**Andre** · 17-05-2021, 13:43

I replaced the pilot bearing this weekend because I thought that was the problem.

- I've also put a screw to prevent the clutch ratchet from resetting and pulled the quadrant to the max so that I would make sure the clutch was disengaging and that didn't work. Problem is still there.
- Reverse doesn't grind more that it did before the problem appeared. I get a grind some times in reverse but I thought that was normal.
- Also, when fully stopped, if I go to second before going into first, even if I do it really quick, I get no grind at all. Synchros? I've replaced them all but I might have missed something...
- I didn't replace the gearbox bearings because they seemed to be fine (that might have been dumb...).
- If I engage the clutch and wait 2 seconds before putting the 1st gear I get no grind. That only happens if I put the first immediately after I engage the clutch.

It surely has something to do with the input shaft spinning long after I press the clutch.

Any more ideas?
Thanks a lot for the input guys.

**mrmk2** · 17-05-2021, 17:22

Too little preload on the mainaxle maybe? But if you go third and then first and it still scrapes there is something spinning up the input shaft.

**Colr6** · 17-05-2021, 19:19

What oil are you using ?

**Andre** · 17-05-2021, 23:16

If I go to 3rd or 2nd before doing 1st, it engages just fine. That's why i'm thinking the synchro on 1st gear is shot (although it was changed for a new one during the rebuild).

For some reason first gear cant stop the input shaft

**Andre** · 17-05-2021, 23:17

Originally Posted by mrmk2

Too little preload on the mainaxle maybe? But if you go third and then first and it still scrapes there is something spinning up the input shaft.

If I go to 3rd or 2nd before doing 1st, it engages just fine. That's why i'm thinking the synchro on 1st gear is shot (although it was changed for a new one during the rebuild).

For some reason first gear cant stop the input shaft

**Andre** · 17-05-2021, 23:18

Originally Posted by Colr6

What oil are you using ?

ATF. The right one I think

**mrmk2** · 18-05-2021, 15:08

Ok, then it sounds like you have to take the box out and split it again. All new syncs or just part of it? I mean synkpacks?

**Andre** · 19-05-2021, 14:21

Originally Posted by mrmk2

Ok, then it sounds like you have to take the box out and split it again. All new syncs or just part of it? I mean synkpacks?

Changed all Synchros. The 1st and 2nd included the 3 parts. I bought them from the States and, honestly, I didn't like the look of them, but they were brand new.
Shouldn't the preload be used on new bearings to account for them to bead in? I mean, Aren't they supposed to spin free after a while?
I will not be taking the gearbox out again for now... So, 2nd gear before 1st will be be for now.

Thanks for all the input guys.