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Hi,

Has anyone experienced this problem and solved it or can narrow down the cause of it?.......or have a hotline to Mildred?

I travelled 300 miles on the motorway last weekend to have a bespoke exhaust fitted. All good on that score. Unfortunately I picked up a rumbling on the last 80 miles that sounds like it's from behind the driver but I could be wrong. Just in time for summer.[:0]

It happened roughly between 65 - 70mph and was much louder on the overun. Pressing down on the clutch pedal removed the rumbling altogether but it returned when re-engaged. Engine revs and gear selected made no difference, it appeared directly related to road speed. Driving around 80mph, below 60mph and town driving removed the noise on the way home. I'm possibly thinking a worn bearing in the rear axle or CV joint in the propshaft but which one?

Rear axle - recon 3.08 unit about 11 years old but only done about 10,000 miles since. Always topped up with correct oil but just started to weep / leak through the oil housing gasket at the front, so I'll have to change the gasket and oil seal anyway. Oil level was good as it only needed a tiny amount to top up.

Propshaft - Obtained with my V8 conversion kit about 18 years ago, maybe done about 12,000 miles. No visible signs of anything wrong.

Gearbox - Original unit done about 80,000 miles, the last 12,000 miles with a V8. I've always treated it sympathetically, especially when cold and always topped up with the recommended oil (not ATF). However,last year I drained and changed to ATF as I couln't get hold of right stuff locally and wanted to see if the gearchange into second was really smoother. (Yes it is) The gearbox mounting rubber was changed last year but I'm planning to change the gearbox extension bushes this winter as they are starting to look worn. I can't feel any vibration through the gearstick and the gears engage fine.

Bushes - Hard type Triumphtune solid bushes locate the rear axle and all look in good condition and passed the recent MOT, no wiggles under acceleration or braking. Polybushes for road cars weren't around at the time when they were fitted.

Anyone come across this type of noise before?

Thanks,


Adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991

Hmmm tricky,

My thoughts would be:

Most likely : Propshaft joints - may have dried out or just showing some wear. recently replaced mine as I also ha d a rear end rumble that was worse on over-run.

Others I'd consider:
Gearbox - possible leak or in need of top up or potential problem, it has done a fair few miles.
Clutch release bearing
Possibly wheel bearing????

<b>2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)</b>

Adam, it's really hard to say cos there are several bearings & joints working back there. Get it on a hoist & go thru each joint & bearing. The propshaft is the easiest to fix so keep your fingers crossed.


Never say die. At least not while you're still breathing.

Wayne - Thanks for the thoughts.

Propshaft sounds the prime suspect based on your experience. I'll drop it and look for slop in the joints first.

Gearbox topped up and sounds quiet from that direction but as you say it has mileage on it. Clutch bearing is quiet when changing gear, in - out - neutral etc so hopefully wouldn't act up like this. I thought of rear wheel bearings but there's no rumbling on cornering fast slow braking accelerating or constant speed.

Peter - Thanks for input. As you say the propshaft is first call. I wish I had a hoist. It's trolley jack and axle stands and lots of crawling around for me.

Whilst looking for a propshaft reconditioners I found this info on a website <font color="blue"> <i>"Most propshaft vibrations are worse within a 15-25mph band. i.e. comes in at 50mph and goes at 65mph. If the vibration is over the complete speed range either the propshaft has been bent or damage has occured to other transmission components (gearbox or differential) " </i> </font id="blue"> This makes it sound more like the propshaft.

Thanks,

Adam

I had mine remanufactured by http://www.baileymorris.co.uk/ as the Grinnall has a bespoke propshaft. Very satisfied.

The only other thing I think that would make a rumble apart from Diff itself is a pinion bearing - but I reckon the prop is favourite as it seems to match my symptoms.

Wayne

<b>2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)</b>

Cheers Wayne!

I lifted that quote from Bailey Morris's sister company Propshaft Services based near Heathrow. I work close to the airport so this could be the handy option.

Mine's an S & S V8 conversion propshaft which I believe is shorter than other TR7V8 suppliers. I can either buy an exchange item through them or go direct to a reconditioners like Bailey Morris and save on the postage.

I'll know better when I drop the propshaft, probably this weekend.

Thanks,

Adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by PeterTR7V8</i>

Adam, it's really hard to say cos there are several bearings & joints working back there...<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
Years ago I had the same problem. Seemed to be coming from the rear RH side. Turned out to be the LH front wheel bearing [B)]
So I'd stick to Peter's advice and check everything ...

<center>
<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (now completely dismantled)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC</font id="blue">
<font color="red">http://tr7beans.blogspot.com/</i></font id="red"></center>

Hiya.

Well it's taken me yonks to find what I've been looking for - but persistance paid off!

I knew I'd read on another forum a similar problem to this. Like most on here I'd be thinking propshaft - but have a read of the following. I've done a load of cutting and pasting. The thread is referring to Dolomite Sprints.

Here goes:

A friend of mine has a yellow dolomite sprint and has been at his wits end for 2 years with a really annoying vibration inside the cabin which occurs around 2000 rpm. Hess been to various garages, had clutches changed, prop shafts balanced, rubber mounts changed etc, you name it he's changed it! No one has been able to fix the problem until recently when we put out heads together. As a last resort we took the engine out, had the crank, flywheel, clutch, rods, pistons all dynamically balanced, rebuilt the engine and the problem still existed and he was moments away from selling the car. When he originally purchased the car the price was quite low and we believe the reason why was the problem was so difficult to detect and the owners had given up and passed the car onto him. When I looked at this problem logically I decided that the sound must be transmitting from the engine and gearbox to the car in some way and that it wouldn't matter if you had the roughest, shakiest engine on the planet, there's no way the the vibrations could actually get through to the car as bad as they do now. We checked all round the engine - nothing was touching, the engine wobbled about nicely in the bay and you could see the front engine mounts were displacing the vibration nicely but yet there was still this annoying vibration in the car. I said to my friend, it has to be a simple case of disconnecting things, one by one, until we find out what's causing the problem, I gave the example of if I was superman, and could hold the engine in place with no engine or gearbox mounts, exhaust or anything that could transmit sound or vibration, and engine the noise would have to stop as it would just be hovering there in limbo. We both laughed and agreed. We started by taking the 2 front engine mounts off and holding the engine over the engine bay with an engine crane but the noise still persisted inside the car. Before removing the exhaust, which we knew was going to be noisy, we dropped the gearbox mount and inspected it. It was in perfect condition - no splits or cracks or fouling of any metal and looked good condition, but when we started the engine the noise had miraculously gone - meaning the problem was the rear gearbox mount. We were frustrated because we couldn't see what was wrong with the mount. We decided to look underneath my car and take my gearbox mount off so we could physically compare the 2 and if necessary swap the 2 mounts over to see if the fault moved onto my car, but immediately when going underneath my car we noticed my gearbox wobbled up and down nicely as if it was nicely balanced on a spring and the rubber was nice and flexible, unlike the gearbox mount on his car. I would also like to add that we have had 2 replacement gearbox mounts on his car over the last few years up to this point so assumed this would not be the fault. It turns out that the gearbox mounts sold by Rimmer Brothers and the gearbox mounts that are sold currently by a seller on eBay are of a very hard rubber compound which doesn't have any give in it at all, so the purpose of this post is to ask you if your car is really noisy around the 2000rpm mark? If so have you purchased a new gearbox mount recently? If the answer's yes, inspect your rear gearbox box mount, this could well be the problem with your car. My friend loves driving his car and is going to keep it! I found an old gearbox mount I had knocking about and gave it to him, he is happy as a pig in S**t now!! happy days...Please post back if you have any input on this or if you have time to get under your car and bounce your gear box... does it just sit there and you have to really push hard to get it to flex or can you bounce it up and down with a finger??

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I had the same problem, I bought all new engine & gearbox mountings, the vibration was horrendous so I re-fitted a soggy old gearbox mount & the vibration dissapeared. The new re-manufactured mounts are far too hard.

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Hello all,
my original gearbox mount seemed rediculously worn, so I bought a new one from Rimmers. A good sturdy mount I thought. Having tightened up the nilock nut to what seemed a reasonable torque, I reversed the car off the drive to have my daughter say " we never had that noise before". Allowing the newness to wear off a bit has now resulted in a noisy front bearing on the gearbox. I was going to post a question on the correct torque for it as it doesn't seem to be mentioned anywhere. I am now resigned to removing the box and fitting a new bearing. Does anyone know of a decent mount supplier?

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I tried 2 new ones before re-fitting my old one. The first from Rimmers the second from Numpty.

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[The Sprint and TR7/8 5 speed share the same gearbox mounting rubber - forgot to mention that.]

What do you make of that then?

Shaun.

http://www.flickr.com/photos/12691409@N08/

Any update on this?

Shaun

http://www.flickr.com/photos/12691409@N08/

Hi,

I recently replaced my wobbly jelly gearbox mount with a new item from Robsport. The vibration was present before and after changing it so don't think it was down to the mount.

I've had my propshaft inspected and the spline on the front CV joint has a wear point / high spot where it's sticking and causing the vibration. Basically the prop has to be replaced.

They can manufacture one using larger SD1 type CV joints in a couple of days at a competitive price but I need to check if it will clear the remote gearstick housing first. They've given me a SD1 propshaft from their stores to bolt up to the gearbox and test for clearance. If all's well it will take a couple of days to have one made. If not they can make a prop with U/J's which are narrower but it'll take 2 weeks to manufacture and cost about 40% more. (U/J's are rebuildable, CV's aren't) We'll see which route I have to take.

Adam

Update - The SD1 prop fits under the remote gearbox housing (brand new bushes) with about 4 - 5mm to spare, about half the previous amount.