LT77 gearbox baulkplate rubbing

Gargo

Gargo

Active Member
Hi all,
Taking the car for a fast test drive I've found fast cornering with power on is sometimes causing, what I think is, the prop-shaft UJ to hit something. (I can hear the noise)
Our car has an SD1 gearbox fitted, here is a picture of what I think is the offending UJ.
dsc00606.jpg

I remember tightening the nut on the stud squashing the rubber gromet, in the lower middle of the picture. Does anyone know what it is or was for? The Haynes manual doesn't show rubber here at all.
Am I ok to lose this rubber as I think I may have pulled the rear of the gearbox down causing the UJ to rub on the metal lower right :oops:

Question again:
What is the rubber on the lower stud for?

Thanks,
Gavin.
 
Re: Prop-shaft rubbing - help

I have yet to look under my car but I too seem to have a noise coming from under the transmission tunnel when I pull away to the left only, it sounds like something is banging the bodywork under the tunnel, I thought it could be the propshaft but I haven't touched anything. Does yours sound like a knocking under the transmission tunnel?
 
Re: Prop-shaft rubbing - help

Can you feel anything in the gear lever when the noise occurs? Does it occur in any gear or specific ones? My old LT77-fitted car rattled in 2nd on acceleration, and it turned out the remote selector bushes had perished and the remote was sagging and fouling on the prop.
 
Re: Prop-shaft rubbing - help

Yes, under the transmission tunnel at the front; it's a very solid loud knocking......I'm sure it's the UJ

Was just off the phone to Tim, who put the SD1 gearbox in the P6. He says the rubber is from the SD1 as are the rubber mounting blocks. The thick metal cross member is part P6 part SD1. He offered both up and ended up cutting both and welding them together, so I'll remove the cross member and have a good look at what I have done by thighening up the lower rubber.
 
Re: Prop-shaft rubbing - help

Gargo said:
Yes, under the transmission tunnel at the front; it's a very solid loud knocking......I'm sure it's the UJ
Click to expand...

Sounds the same as me. I have an SD1 bottom end and definitely a SD1 bellhousing, maybe a full box but it seems we have similar issues. As I say mine only happens when pulling away to the left. I think the drive train is twisting allowing the prop to foul. Strange that mine has just started and yours is after you tightened the rubber. Does this guy think its because you fiddled with the rubber because I suspect my problem is being caused by a knackered rear mount for the gearbox.

You say the noise happens when you corner, does it only happen sometimes? Is it only on cornering and does it only happen when you turn only one way?
 
Re: Prop-shaft rubbing - help

Gargo said:
Question again:
What is the rubber on the lower stud for?

Thanks,
Gavin.
Click to expand...

It's not supposed to be done up tight, there's supposed to be a gap, so the gearbox is supported on the cotton reel mountings, the one in the centre is just there to limit any movement.
 
Re: Prop-shaft rubbing - help

Hi, it is not clear in the photo, but where is the evidence of rubbing on the UJ
and the car/crossmember?

Colin
 
Re: Prop-shaft rubbing - help

Hi Colin, you are correct nothing can be seen in the photo and I'll even say I could not see anything when under the car, but as it was cold and wet I didn't spend long under there. The car has only done it two or three times in the one or two miles I've driven it, so I'd not expect to show too much yet. I'd rather find and fix than it break.

HarveyP6, Yes this is makes sence. It is the only thing I've altered here, since we put the Jag IRS in. The rubber was compressing as I did a spanner check on the car and now the knocking. I'll losen it off again and if the knocking stops then that is it.

Mikep, We always had the knocking as you say when going to the left; I could also see where three screws, on the right hand side of the gearbox at the rear, have been rubbing the transmission tunnel. These I assume are something to do with the gear selection mech. I just hoping that it all only needs shimmed.
I'd also check the rear UJ on the cross member. We had the front diff rubber mount go and the front of the diff was lifting allowing the rear UJ to hit the transmission tunnel.
I'll keep you informed to what I find.
 
I had a longer look under the car and I think I've found the problem. The SD1 gearbox, the LT77 baulkplate assemble is knocking against the transmission tunnel.
Here is the tunnel looking forwards and upwards, I've circled the knocking bolt head:
copy-of-dsc00607.jpg


Here is a closer picture where you can see the bodyseal has been rubbed away:
copy-of-dsc00630.jpg


And an overview of the gearbox, '1' is pointing to the bolt head circled in the pictures:
gbxremote01.png


I'm not sure how to fix it without taking the gearbox out and modifying the baulkhead plate. I'm not worried that the prop-shaft is going to explod so I'll carry on for now.
Mikep : If you could look under your car it would be interesting to see if this is your poblem too.

Gav.
P.S. Can I change the Title of this thread now I know it's not the propshaft?
 
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