[bron5on]

As the title suggests I've got a couple of problems with my sierra. But first a bit of background info. It's an 89 model factory half and half SJ50/70. Now lifted with a 1.6 16v motor running original gearbox with excedy HD clutch (I completely destroyed the standard duty one) and 4.16 gears in the transfer. I've been on holidays for a bit and returned home last week. The zuk has been sitting in the shed gathering rat shit for 6 months. She started up fine but has developed a couple of minor problems after a couple days driving. The first is a noise that sounds a bit like a cricket chirping. I can hear it while cruising sometimes but more so with the foot off the gas when coasting or pulling up. The sound disappears when I push the clutch pedal in once I get past the friction point. Doesn't seem to make the sound when accelerating but my zuk is loud so it's hard to tell. My guess is spigot or throwout bearing. I'm leaning toward the latter.

The second is a low speed vibration. Pulling up at lights, taking off or cruising through the car park often but not always seems to induce a bit of a wobble. Sometimes it's a minor vibration, at others it gets quite a shudder up. Here I was leaning toward a uni joint in the jack shaft maybe as the gear stick can get quite a shake up. The unis don't seem too bad but I'm no expert in this department. What I did notice under the car is some sort of collar at the rear of the gearbox just before the first uni that is loose. Check the picture I took below:


The yellow arrow indicates the suspect part. I can freely move it with my fingers. It rotates (red arrow) back and forth by almost 10mm. What is it and could this be the source of the vibrations? Any help much appreciated as nearly ready to sell the bloody thing!

Cheers people!

[boostedbrick]

What you have said sounds spot on, first bit sounds like your throwout bearing..

The second, sounds like a jack shaft uni.. Its only four bolts to remove, pull it out and give the uni a twist and see if either have any play in them. None of the boxes i have owned have had that black bit on, im guessing its just a dust cover, that you can remove when you pull your jack shaft out.

[TryHard]

hmmmm question i found the same thing with my zook ..ever since i put the mighty kong case in the other week sometimes when slowing down .. ?

should i look at the jack shaft uni ? i though it must be because of the solid mounts im running ?

[boostedbrick]

I ran solids with my 4.9s.. Seemed smoother than with the rubber ones.. My last jack shaft, I couldn't feel play with it fitted. But was very noticeable once removed. Also noticeable when it took the gearbox output seal out

[steak_knife]

bron5on wrote:

The yellow arrow indicates the suspect part. I can freely move it with my fingers. It rotates (red arrow) back and forth by almost 10mm. What is it and could this be the source of the vibrations? Any help much appreciated as nearly ready to sell the bloody thing!

Cheers people!

Tis an oil slinger, you coud weld it in place or remove it.
Or take it to a drive shaft shop, get them to make sure it's on true & get new uni's fitted at the same time..

[bron5on]

Thanks for the input lads. Looks like the shaft is coming out for an inspection. I'll have to drop the gearbox out anyways for the new throwout. I never mentioned the t-case mounts I'm using. They're mazda items. There's a thread on them on here somewhere. Similar to factory but a bit heavier duty in construction. Taller from memory too I think.

Bronson

[steak_knife]

bron5on wrote:

Thanks for the input lads. Looks like the shaft is coming out for an inspection. I'll have to drop the gearbox out anyways for the new throwout. I never mentioned the t-case mounts I'm using. They're mazda items. There's a thread on them on here somewhere. Similar to factory but a bit heavier duty in construction. Taller from memory too I think.

Bronson

part number????

[bron5on]

steak_knife wrote:

bron5on wrote:

Thanks for the input lads. Looks like the shaft is coming out for an inspection. I'll have to drop the gearbox out anyways for the new throwout. I never mentioned the t-case mounts I'm using. They're mazda items. There's a thread on them on here somewhere. Similar to factory but a bit heavier duty in construction. Taller from memory too I think.

Bronson

part number????

Post number 7 on this page has a pic and part number.

[steak_knife]

Cheer's!!!!

[bron5on]

Indeed one of the unis in the jack shaft was stuffed. Felt fine bolted up but once removed the uni at the transfer end was seizing up in one plane of movement. No wonder it was vibrating intermittently. New uni and all is well. I was a little concerned when I got it back together only to realise I assembled it 180 degrees out (I marked the shaft and flange before I separated them and forgot to look again til it was too late) but it seems to be fine after a couple of drives. Thanks again peoples!

[steak_knife]

bron5on wrote:

Indeed one of the unis in the jack shaft was stuffed. Felt fine bolted up but once removed the uni at the transfer end was seizing up in one plane of movement. No wonder it was vibrating intermittently. New uni and all is well. I was a little concerned when I got it back together only to realise I assembled it 180 degrees out (I marked the shaft and flange before I separated them and forgot to look again til it was too late) but it seems to be fine after a couple of drives. Thanks again peoples!

Doesn't matter.....

[bron5on]

steak_knife wrote:

bron5on wrote:

Indeed one of the unis in the jack shaft was stuffed. Felt fine bolted up but once removed the uni at the transfer end was seizing up in one plane of movement. No wonder it was vibrating intermittently. New uni and all is well. I was a little concerned when I got it back together only to realise I assembled it 180 degrees out (I marked the shaft and flange before I separated them and forgot to look again til it was too late) but it seems to be fine after a couple of drives. Thanks again peoples!

Doesn't matter.....

Cheers Stekky, that's good to know!