Shuddering 1st gear

[mistaboz]

Hi. I have a 93 Sierra.
On take off its shuddering in 1st gear low and high range.
All other gears seem to be ok.
Thought it was a uni so pulled them out and they check all ok.
Thought it could be bent tailshaft but ruled that out as it would get worse the quicker I was going.
Ive got 2 inch suspension lift and 2 inch shackles so dont think it would be axle wrap, as its just started doing it the other night after a big hill climb.
Any ideas?


Cheers PAUL..

[Pinball]

clutch starting to play up??

first would put the most strain on the friction pads.. is it worse in low range?

Spock

[mistaboz]

Bout the same in low range.
Just put a new hd clutch in it about 2 months ago.

[droopypete]

check transfer mounts.
Peter.

[nads]

And engine mounts.

first low should be low enouhg to release the clutch fully before giving it any throttle under most cirumstances.

[dreamz]

yea ive got the same problem and ive busted an engine mount sadface

[Spike_Sierra]

check rubber tcase mounts, i changed mine and it removed all shuddering, i changed mine to solid body lift blocks, and bolts all the way through.

[mistaboz]

Checked t/case mounts and all seem to be ok.
Gearbox mount rubber was a little damaged so I have pulled that out and am getting a new one.
What actually braken with the engine mount? Is it the centre bolt?

Cheers PAUL..

ps. Where can I get the rear engine/gearbox mount from?

[lay80n]

The rubber in the mount breaks. Even though you have a new clutch, did you change the rear main seal at the time. or machine the flywheel??. Have you flooded the bell housing in mud recently.

Layto....

[mistaboz]

I did machine the fly wheel.
Didn't replace the rear main seal though.
Haven't flooded the bell housing in mud recently (since having the new clutch in and getting fly wheel machined).

I levered the engine mounts and they appeared to be ok. Although having a search told me that I won't be able to tell if the engine mounts are broken until I pull them out. Will pull them out tonight and check them properly.

PAUL..

[christover1]

start with passenger side engine mount, they most often break, drivers side is rare to bust.

the engine mounts can stretch the rubber with age, and the 2 metal bits can rumble together without a full break.

I believe the heavier duty vit mounts fit, but lift the motor a bees wing.
Some vits use same eng mount as sierras do.

It could be mud in the clutch, and if so could fix itself if ya lucky.

I put a breather on me bell housing, that helps, even though I have not sealed the bottom up (otherwise you just keep the oil and water in)

I've also used stronger t-case mounts

christover

[mistaboz]

Thanks for the replies. Will check it out a bit more tonight.

christover - with the mud in the clutch bit... the vibration has been there slightly for quite some time, just lately it has become worse. Even before I changed the clutch. I guess anything is possible though. Lets hope its an engine mount.

PAUL..

[mistaboz]

Pulled the passenger side engine mount out tonight and its broken.
Will get a replacement in the next couple of days and then post up on here how I went.

Thanks for the replies PAUL..

[ronoor]

hm i remember a bloke telling u about a brokin mount 3-4 weeks ago . ha good that u found it but 'be fore we hit the big stuff . cheers ron