Differential backlash / vibration

[Mark Serj]

I took mega care to align the box to the motor Rich, using the dowels etc. Next time I take it for a drive I'll analyse the vibes again.

Cheers

Mark

[Guest]

Stick a camera underneath on the driveline and record it.

I did this on the Jaguar.
It was absolutely horrifying to observe what was going on under there.
It only had stability cos of the "depleted uranium weight" of the rear axle..

With the Stag I reckon you literally won't believe the crazy movements taking place.
Ignorance is bliss.

[richardthestag]

camera will shake off surely

I hear all that you say and most of it makes sense. not that I agree with lots of it though.

Triumph were in the business of building cars not racecars. And one eye was always on the purse strings. especially so after BL debacle. Aside from the obvious design faults in the engine what Triumph did in 1970 was a good effort compared to what else was available.

Comfort, features, performance, stopping and handling all rated well at the time

Technology and design ideas evolve which is why we are here in 2017 listening to how **** it all is

[Guest]

Triumph were in the business of building cars not racecars.

No, (Standard-) Triumph were a bankrupt entity recovered from Bankrupt Standard motor co.
The entire drive train comes from Standard, not Triumph.
The Stag gearbox is Standard Vanguard/TR2 with some tweaks.

Being as there was no money to develop another drive train and by the time the Stag came along they were sharing house with another bankrupt Oxford and Abingdon group, then it's nothing to do with racecars.

They had a Gleason patent in house axle, so they had no way of doing anything about it.
Problem is, it shares ZILCH components with any other Gleason in house axle, and the MG stuff was banjo crap from even older times.
...so it has the same 1950s massive weaknesses (such as the timken carrier bearings spinning on the carrier housing), and has bearings used nowhere else in the industry.

They just carried on getting by and attempting to improve some of the weaker points like the laygear and pinion bearings, then chucking away the vintage overdrive unit, fitting a more modern one with even higher power losses.

The only race cars that worked - and it MUST BE SAID, were the Dolomite sprints which are based on the Stag with the same transmission, won a major European championship, as well as many other things.
They often did not finish because something broke in the drive train.

When it came to doing "race cars", based on the SD1, they chucked the weak old Triumph stuff away and started all over again from scratch.
The TR8 was the final evolution of that idea, like it or leave it.

[richardthestag]

I think you missed the whole point of my last message, maybe I was too subtle.

I will try again..
- I get the impression that you feel everything made by Triumph in the 60s and 70s should have been done to a current car standards, which must have been race car standards back then .
- That aint what they was in business for! They made road cars for normal herberts like me.
- Not only that but when they did make them, they didn't do a bad job compared to the rest of their contemporary marketplace.
- they also tried to make a profit, ok not so good at that bit then But think how bad it would have been had everything been designed and built to the standards that I think you are alluding to? Stag would have cost as much as a contemporary Ferrari, yeah that would have worked.

All the stuff you wrote about standard gearboxes and no money and diffs and overdrives and is to me like saying the Jag XK 6 pot powerplant was sh..t in the 1980s because it was developed in the 1940's. Was a manufacturer in the late 1960s not allowed to use what was perfectly good in house technology available at that time? Should they have re created the wheel each time? maybe you forget that when the Stag started development we were just out of the austerity caused by WW2 which concluded just 20 years earlier. I am not being obtuse, I just don't get your point sorry

Timken carrier bearing you mention is a standard size, any bearing supplier worth talking to will have one on the shelf. That Triumph had the foresight to use such a widely available bearing should be applauded. Ok the design is unconventional but it works (when the market is not flooded with cheap made from butter poor replicas of the Timken product).

Wouldn't the world of classic cars be a boring place had everything since the war been built to the same design, how could ideas have evolved had that been the case? Nobody would have made mistakes trying to push the envelope!

yeah and about that BL race program for sprints, TR7s and SD1s, Pretty much all totally and utterly re engineered by the likes of Messrs Walkinshaw etc. Impressive as they were the factory product was about as far away from the race car as it could possibly be. They chucked pretty much everything away not just the sh..t Triumph stuff

[Guest]

yeah and about that BL race program for sprints, TR7s and SD1s, Pretty much all totally and utterly re engineered by the likes of Messrs Walkinshaw etc.

Impressive as they were the factory product was about as far away from the race car as it could possibly be.
They chucked pretty much everything away not just the sh..t Triumph stuff

I don't think you know anything about the sprint race engine program or much about the mechanical bits in the Stag and Dolomite.
The engine was completely stock, the only thing that RALPH BROAD worked on was the head and cam.
Broadspeed was in Southam a stone's throw from Coventry.
I had one of his race cylinder heads.

The gearbox was totally stock with just the STN53 close ratio set stuck inside.
The clutch a special cover from AP racing but otherwise totally stock.
The LSD totally stock- I bought 10 in boxes when they were still available in the 80s and fitted them in loads of TR6 axles.

Walkinshaw?
The biggest con man in the biz. What did he ever develop for the TR8?
Most of the stuff was done by Eales in Coventry.

The v12 Jag engines from TWR, all copied from Tullius work in the USA.
The XJ220, only cos he could get the V64V for scrap money after the demise of Group B, and after he had conned loads of people out of fitting the V12 and sticking an engine in half the size, with half the number of cylinders.
The DB7 ouch what a mess...
TW, was only after the money, always a 1 way ticket, which is why he went under.

No,- in this respect I have to congratulate Triumph with their sprint program.
Luckily Walkinshaw had nothing at all to do with it.

With very little money, and a not terribly reliable engine, they managed to do an excellent job, which makes cars like Bunkus in Germany show fast porsches even today a clean pair of back wheels.




I have a lot of respect for the sprint stuff, the gearbox and rear axle is practically identical to the Stag internally.
Do you know about the F3 engine program?
The only reason it failed, it was outclassed by better more modern stuff like Toyota... at least then.

Bunkus_12.jpg

[new to this]

I don't think you know anything about the sprint race engine program or much about the mechanical bits in the Stag and Dolomite.
The engine was completely stock, the only thing that RALPH BROAD worked on was the head and cam.
Broadspeed was in Southam a stone's throw from Coventry.
I had one of his race cylinder heads.

The gearbox was totally stock with just the STN53 close ratio set stuck inside.
The clutch a special cover from AP racing but otherwise totally stock.
The LSD totally stock- I bought 10 in boxes when they were still available in the 80s and fitted them in loads of TR6 axles.

Walkinshaw?
The biggest con man in the biz. What did he ever develop for the TR8?
Most of the stuff was done by Eales in Coventry.

The v12 Jag engines from TWR, all copied from Tullius work in the USA.
The XJ220, only cos he could get the V64V for scrap money after the demise of Group B, and after he had conned loads of people out of fitting the V12 and sticking an engine in half the size, with half the number of cylinders.
The DB7 ouch what a mess...
TW, was only after the money, always a 1 way ticket, which is why he went under.

No,- in this respect I have to congratulate Triumph with their sprint program.
Luckily Walkinshaw had nothing at all to do with it.

With very little money, and a not terribly reliable engine, they managed to do an excellent job, which makes cars like Bunkus in Germany show fast porsches even today a clean pair of back wheels.




I have a lot of respect for the sprint stuff, the gearbox and rear axle is practically identical to the Stag internally.
Do you know about the F3 engine program?
The only reason it failed, it was outclassed by better more modern stuff like Toyota... at least then.

[ATTACH=CONFIG]41552[/ATTACH]

i do like the sprints my self, but if you think the stag rust,you haven't seen a dolomite boy they rust how are you getting on with the one you were working on

[GDPR]

Funny how things happen - this Stag came in today with I think pretty much what you have Mark - I'm dropping out the diff to sort out the thrusts and lose the huge backlash in the differential section - ignore the somewhat knackered outer driveshaft UJ in the video as that will be done at the same time.

If I can find someone to hold the camera, and assuming my 50p hasn't run out in the SOC meter by then, I may post a repair video...

https://youtu.be/gK6yYOIoNCI

[richardthestag]

Funny how things happen - this Stag came in today with I think pretty much what you have Mark - I'm dropping out the diff to sort out the thrusts and lose the huge backlash in the differential section - ignore the somewhat knackered outer driveshaft UJ in the video as that will be done at the same time.

If I can find someone to hold the camera, and assuming my 50p hasn't run out in the SOC meter by then, I may post a repair video...

https://youtu.be/gK6yYOIoNCI

way more backlash than mine, did it whine also Russ?

Interested to see how you get on with this as Diff is pretty much the last thing that I have yet to understand and work on. I made one out of meccano which I was quite pleased with

The reason I ask is my epic 72 Range Rover rebuild programme has got to axle rebuilds, one of the diffs is very sloppy and as always I would rather rebuild than replace if at all possible

20170805_184631.jpg

[GDPR]

I think you may need to concentrate on finding a body first

As I said it will be likely down to seeing if I can get someone to hold the camera at the right time, and my 50p lasting

This diff does make some noise, but not bad, and no worse than the overdrive so worth trying a repair first

[richardthestag]

lots of stuff

Calm down mate, this is an internet forum and I am only expressing an opinion

so stock engine apart from the heads and cams, and probably pistons, rods and sump (pretty sure they had to baffle them due to oil issues - maybe that was the TR8 programme). maybe the oilpump was stock? I recall they had issues with the hex drive - maybe that was rover v8 as well, I was 9 when the sprint programme was all done and dusted. I do recall seeing the Rovers on track though, awesome.

And Stock gearbox apart from everything inside it.

we are arguing same point old chap, it takes 2 to argue so no more from me on this

[richardthestag]

I think you may need to concentrate on finding a body first

As I said it will be likely down to seeing if I can get someone to hold the camera at the right time, and my 50p lasting

This diff does make some noise, but not bad, and no worse than the overdrive so worth trying a repair first

Ha

Slight thread drift but..

getting on for 200hours to get to this point

This is the bits that I threw away! Got £20 for that lot, beer for me a dad up on Exmoor

20170305_131756.jpg

[Guest]

so stock engine apart from the heads and cams, and probably pistons, rods and sump

And Stock gearbox apart from everything inside it.

Triumph 1970s race car differences between stock and race were very minor.
You can read all about it in the homologation papers.

The STOCK pistons on a Dolomite sprint were made by MAHLE.
They didn't need to change them.
The rods are steel as were the early nitrided cranks.
Bearings are Vandervell from the factory same size and shape identical to STAG

There is ONLY ONE CAM in a dolomite sprint, which is identical profile to the STAG, so they made the ST profile, which is available today easily.
(the extra 8 valves of the 16 compared with the Stag head are operated by rockers).

You could fit the same profile in a Stag if you were mad enough!
All the rest apart from flowing the head was bog standard.

They did nothing to the sump as it doesn't suffer badly from the factory from surge- as per Stag.
Oil pump identical to STAG, bog standard head gasket.

The gears in the gearbox are identical to the STAG and Dolomite std ones, they changed the ratios by changing the input shaft, it was only the RALLY gearbox which changed the 2nd and 3rd gears.
The rest was all standard, usually skimming 0.020 of the syncro rings to prevent them from bottoming under race type gear changes.

I had one of the Dolomite race J type overdrive units, used in rally cars.
It was brutal and snatched your head off.
Pressure was about 700psi (much more than the stock 380-460psi usual units).
The Dolomite was not a good rally car, because both the Escort and the Sunbeam Lotus were better, faster and had proper factory support.

Andy in OZ uses the ST53 set in his 2.5 (2.7) pi, with a special clutch plate.
You could fit this in a Stag using some imagination.
It's not my cup of tea.

So, you see the only thing in a race sprint which changes fundamentally from the road car was the camshaft, the 48DCOE webers and of course the exhaust manifold.
Not bad when you consider how much you have to fork out on a BDA Escort eh?

Ask me how I know?
We had one STN53 gear set in our TR4 race car in Germany which won the EU historic race car championship outright 1993.
I told them the dolly set was crap, and with some little help from ZF in Saarbrucken, we made a ONE OFF close ratio set with 2 straight cut gears in it as a "homer".
Telling people stuff is crap, usually works out, because it is not a problem to do better, especially in Germany when there was plenty of money to fund doing it right.

The rear axle was a QUAIFE "LSD" which was also crap, - I told them so.
They got me to change it - I fitted a Dolomite sprint plate type LSD in it instead.
I managed to squeeze an extra 4bhp at the wheels by building it right.

The rear axle change from quaife to salisbury gained us 4s a lap immediately, and the 2 straight gears saved us about 8-9bhp (in 3rd gear especially) and 4-5 in the lower gears.

In view of the cost of each additional 5bhp at that level, the 2000-3000 quid for the axle and gearbox was peanuts.

By the time I got round to sorting out the suspension properly (swopped out the TR3-4 zero castor uprights to TR5-6 ones with 3-4 degrees castor...) the car was already quicker in the wet than it was in the previous year dry.
There are photos of it leaving a full race Lotus Elan TC standing.

They were the good times.

The TR4-6 don't suffer from transmission vibrations and misalignment much because the prop is stronger and shorter.
The Sprint having a live axle doesn't really have problems at all with this, cos the axle is isolated from the body and the whole drive train much shorter.

The Dolomite sprint rear axle is basically a TR4 live axle with some small changes to use coil springs instead of cart springs.
The proper Dolomite race axle shafts were loads thicker and stronger to prevent flex and oil leaks. I chucked a load away in the 1980s cos nobody wanted 'em!

The Stag was well known from the day one as being a car with drive train problems, as does the 2.5pi.