The Triumph Dolomite Club - Discussion Forum

At this point I'd just say that I changed the engine mounts last month as a sort of last ditch attempt to cure the problem - because they were about the only things (other than the centre bearing) that had never been changed. I knew from this forum that it was nigh on impossible to get OE mountings any more for a 1500 with the correct colour splashes on, but when some did eventually appear on Ebay I got them and put them in. They made no difference. And the old ones had not de-laminated. This problem is not something that happens in first or second gear. Why it improves when the engine warms, I don't know.
I think too, that because I've over-spent on this car (13k so far) it's getting me down a bit.
Alan

That's good news on the engine mountings and well done for finding a correct pair. Although I wouldn't use as much poly as you have I can't come up with a solid argument for which would cause this. Assuming you have tried to get it to vibrate stationary and it will not then the rear end is more likely. But I'm coming around to the propshaft idea, initially I was thinking no because it stops when you dip the clutch. But that ignores that under load it will behave differently plus at the engine revs where you have the problem you're probably near peak torque. At higher revs the power is smoother.

I have two around. The original from my car is I am sure untouched. The one on the car I replaced the joints and had it balanced, I do not recall if I replaced the centre joint. I am certain that prop went back together exactly as it was before but that doesn't make it right. It did change the character of the car though not nearly as severely as you describe on yours and not a problem. All the same - different and not quite as smooth as before. I'll check the phase of the joints on both and report back.

Some adjustment of the prop may help. I think it was on sprints that getting the centre mount bolted on correctly was essential to a smooth life and correct looks wrong to the eye. From memory one side the centre bearing must be above the bracket & the other side it must be below though I've no idea which way round. This lowers the bearing fractionally. Since it costs nothing you could try the same on your car and just see what effect it has. I would also sight along the line of the prop with a laser if you have one and just check it is completely straight left/right. It could be that under torque the prop is kinking and the centre bearing orbiting in it's carrier. A fractionally different line could prevent that.

Separate to this problem I would think about all that poly in the rear suspension. It is known absorb less flex than rubber and in extreme cases, i.e. on race cars, cause cracking & failure of lower links. I would expect much the same to happen over a much longer time frame on a road car.

When I refurb'd the centre bearing using the Ford Transit bearing as a replacement, I noticed that the bearing does not sit in the middle of the rubber carrier, it is actually offset.

If the carrier is fitted upsidedown/ wrong it will be out of position, too high or maybe too low by about 5mm-8mm or 1/4 -3/8 inch approx.

The actual fitting position of the centre bearing seems to vary according to model, most OHV cars seem to have it fitted the way that looks "right" ie with BOTH flanges above the support brackets and bolts in from below. This is how the Carledo was when I bought it as a 1300 and how it still is with a Vauxhall engine and gearbox, a bespoke hybrid prop and a Sprint diff. I had the prop built and balanced by a professional company and have had no issues with it at all. Slant powered cars OTOH, tend to have the o/s flange BELOW the support bracket, resulting in a very odd "wrong" look. This may be to alter the angle of the prop relative to the gearbox. I'm not sure WHY, but i've heard that running the prop EXACTLY in line with the gearbox mainshaft can produce some weird effects too, it needs a slight angular differential to work correctly!

Thinking about this has also dragged up an ancient memory! Back in the 70s, manual Ford Granadas were plagued by similar driveline vibes from new. Not all cars were affected and the levels of problem varied, but it was common enough that Ford tried to do something about it. This resulted in a service bulletin telling dealers how to exactly set up and shim the centre bearing alignment. Sometimes this helped and sometimes it didn't, which confused us workshop types no end!

Eventually (and this is my point) it turned out to be nothing to do with the prop, but something called "clutch thrash vibration" (please don't ask me to explain this cos I don't know!) A re-designed clutch centre plate was eventually made available for affected cars which cured it completely and this modified driven plate became the standard OE replacement.

This "Clutch thrash vibration" is not unique to the Granada but has affected a few other cars over the years, notably MKI and MKII Consuls that I know of, but other makes as well. And MIGHT be the cause of your troubles. As Sherlock Holmes famously said, "Once you have eliminated all other possibilities, whatever is left, however unlikely, must be correct!" I note that you had an O/D box fitted, was the clutch replaced at the same time? It may be that an incorrect or duff driven plate was fitted that brought this on.

Steve

alangraham wrote: ↑Sun Jul 02, 2017 10:30 pm At this point I'd just say that I changed the engine mounts last month as a sort of last ditch attempt to cure the problem - because they were about the only things (other than the centre bearing) that had never been changed. I knew from this forum that it was nigh on impossible to get OE mountings any more for a 1500 with the correct colour splashes on, but when some did eventually appear on Ebay I got them and put them in. They made no difference. And the old ones had not de-laminated. This problem is not something that happens in first or second gear. Why it improves when the engine warms, I don't know.
I think too, that because I've over-spent on this car (13k so far) it's getting me down a bit.
Alan

having followed this thread with intrest, i to had a bad vibration on my 1850 auto.
having followed the advise given i rephased the prop which made it a lot better
but after reading this i realise my vibe gets better when its hot, in really hot weather its not bad at all after a long run it is also at its worst under acceleration.
my car is also fully polybushed and i am wondering if this is the problem
my bushes are a yellow/orange colour, i do not know the make as they were fitted by the previous owner and only in the last 12months.
any suggestions
tony.

An update (2/8/17). With grateful thanks to everyone who replied.
Took the car to a fresh garage - recommended locally as the owner/proprietor has a Sprint - and when run with wheels in the air, vibration occurred at 2.8 revs in every gear. Brown dust around the new UJs aroused suspicion and one was found to be seized in one direction. The balanced propshaft aroused further interest due to the nature of the "unusual" balancing already undertaken.
The propshaft was sent away to a different motor factor for further balancing and for more new UJs (with grease nipples) to be fitted.
On return, and £290 lighter, the vibration is still there but it's very very much improved. There's probably things that can be done to eliminate it altogether but I don't know what they are and the garage has no further ideas.
Sadly it was found that a previous garage had over tightened the two bottom bolts of my expensively reburfished overdrive unit and cracked the alloy beyond repair (of course they denied it). So my heart's in my boots. I need to source a new overdrive casing to transfer the internals to. Finding the original overdrive (for a conversion) was like finding hens teeth so I don't hold out much hope. A case of 2 steps forward, one step back.
Alan

alangraham wrote: ↑Wed Aug 02, 2017 8:55 pm .
Sadly it was found that a previous garage had over tightened the two bottom bolts of my expensively reburfished overdrive unit and cracked the alloy beyond repair (of course they denied it). So my heart's in my boots. I need to source a new overdrive casing to transfer the internals to. Finding the original overdrive (for a conversion) was like finding hens teeth so I don't hold out much hope. A case of 2 steps forward, one step back.
Alan

I saw one for sale only yesterday on Facebook or eBay I think.

Yes, there's one on Ebay but they want £345 for it. It's in similar A1 condition to the one I had refurbished, for which I paid a similar amount - it's now been cracked. Just a clapped out one or an empty shell would suit me better.

This was just the rear ally section I saw.

alangraham wrote: ↑Wed Aug 02, 2017 8:55 pm An update (2/8/17). With grateful thanks to everyone who replied.
Took the car to a fresh garage - recommended locally as the owner/proprietor has a Sprint - and when run with wheels in the air, vibration occurred at 2.8 revs in every gear. Brown dust around the new UJs aroused suspicion and one was found to be seized in one direction. The balanced propshaft aroused further interest due to the nature of the "unusual" balancing already undertaken.
The propshaft was sent away to a different motor factor for further balancing and for more new UJs (with grease nipples) to be fitted.
On return, and £290 lighter, the vibration is still there but it's very very much improved. There's probably things that can be done to eliminate it altogether but I don't know what they are and the garage has no further ideas.
Sadly it was found that a previous garage had over tightened the two bottom bolts of my expensively reburfished overdrive unit and cracked the alloy beyond repair (of course they denied it). So my heart's in my boots. I need to source a new overdrive casing to transfer the internals to. Finding the original overdrive (for a conversion) was like finding hens teeth so I don't hold out much hope. A case of 2 steps forward, one step back.
Alan

Which two bolts did they over tighten? The casing on the unit looks too robust to crack in that manner.

Is it not possible to repair? I know they can stitch engine blocks together, so maybe something similar with the casing? Perhaps drill the casing, put a bolt through to pull it back together, with some sort of expoxy to seal the crack. The bolt provides the strength and the epoxy the seal.

I don't know if any of that is possible, but to avoid a 300 pound plus bill, it might be looking into.

Any chance of a photo of the casing that you need?-I have a couple of Sprint overdrives (if I can find them) that might be suitable for parts.
Alternatively, overdrive repair services in Sheffield may be able to help you.
James

alangraham wrote: ↑Wed Aug 02, 2017 8:55 pm When run with wheels in the air, vibration occurred at 2.8 revs in every gear.

If your vibration is rev related rather than speed related, the source is in the engine/clutch area NOT the driveline!

You either have a stray harmonic causing what is known as a "sympathetic resonance" - or it's clutch thrash vibration! Driveline faults can amplify this in both cases, fixing the driveline faults you found will and has reduced the symptoms, but you need to look elsewhere for the root cause.

Steve

red&black wrote: ↑Thu Aug 03, 2017 9:01 am Any chance of a photo of the casing that you need?-I have a couple of Sprint overdrives (if I can find them) that might be suitable for parts.
Alternatively, overdrive repair services in Sheffield may be able to help you.
James

Or Mike Papworth!

Steve

I have had a case where the corner of one of the lower rear mounting bolt holes has broken away. This was some years ago but I managed to drill and tap the bolt hole a bit deeper sufficient to get a fixing. You could also try fitting studs and use expoxy resin to strengthen the fixing. If I remember correctly the thread is UNC.