Discussion
Driveline angles.
ive had a minor vibration on the car....its bugging me.
comes in at about 80/90, then steadily gets worse to 140 or so.
it it feels like propshaft imbalance, I had that checked, and it was out, but rectified.
the vibration improved.
I checked the gearbox and diff angles, and have the following
gearbox points down at the back by 0.5 degrees.
diff points up at the front by 2.5 degrees....so those faces are not parallel.
the angle of the propshaft is 3 degrees.
so i have a 2 degree from gearbox to prop, and a 0.5 degree angle from prop to diff.
ideally these should be equal, but does anyone know how much tolerence is acceptable....half a degree, quarter degree?? is this variance likely to be the cause of the vibration?
ive had a minor vibration on the car....its bugging me.
comes in at about 80/90, then steadily gets worse to 140 or so.
it it feels like propshaft imbalance, I had that checked, and it was out, but rectified.
the vibration improved.
I checked the gearbox and diff angles, and have the following
gearbox points down at the back by 0.5 degrees.
diff points up at the front by 2.5 degrees....so those faces are not parallel.
the angle of the propshaft is 3 degrees.
so i have a 2 degree from gearbox to prop, and a 0.5 degree angle from prop to diff.
ideally these should be equal, but does anyone know how much tolerence is acceptable....half a degree, quarter degree?? is this variance likely to be the cause of the vibration?
phazed said:
Steve, surely cars with live axles have the angle changed all the time and they don't suffer from vibration.
My Disco has a 55-65 vibration. Box and props were changed, wheels checked etc and no joy, even checked by 2 separate L/R indies, still vibrating!
I think with a live axle the angle of the prop changes, but the parallel"ness" (if thats a word) between the gearbox and the diff flange faces doesn't.....i might be wasting my time, but its the only thing left to resolve....good if i can though.My Disco has a 55-65 vibration. Box and props were changed, wheels checked etc and no joy, even checked by 2 separate L/R indies, still vibrating!
Checked the prop, was within 1 gram, so pretty good
Remade the front diff mounts and gearbox mount, so the prop and gearbox faces are perfectly parallel.
Checked the reaer wheels for balance, one was 40 grammes off!! Which was a surprise, but I always thought wheel balance issues came in at 60 and didn't get progressively worse....but it maybe a contributing factor.
It'll go back together saturday, so let's see how we get on.
Remade the front diff mounts and gearbox mount, so the prop and gearbox faces are perfectly parallel.
Checked the reaer wheels for balance, one was 40 grammes off!! Which was a surprise, but I always thought wheel balance issues came in at 60 and didn't get progressively worse....but it maybe a contributing factor.
It'll go back together saturday, so let's see how we get on.
driveline vibration now gone.
don't actually know if it was wheels/ driveline angle, or a combination of both, but i suspect it was the driveling angle as it had that sort of resonance.
the new gearbox bracket sits a tad lower, so will need to "clearance" the exhaust a little, apart from that......jobs done.
roll on summer
don't actually know if it was wheels/ driveline angle, or a combination of both, but i suspect it was the driveling angle as it had that sort of resonance.
the new gearbox bracket sits a tad lower, so will need to "clearance" the exhaust a little, apart from that......jobs done.
roll on summer
bump steer and tram lining.
With the 235 17 rsr fitted to the front, the car does now have a tendancy to tramline a little on rutted roads. Fitting std 15 fronts, that goes away, but you really notice the increased roll, washout, and tendancy not to go round corners, ...bit of a tradeoff i guess vs corner grip. I wonder if road 17 tyres would have less tendency, as some have reported track type tyres have more tendancy to tramline??
Making sure that bumpsteer was not causing an issue (or making it more noticeable), i fitted rose joints to the track control arms so i could space the arms up or down vs the steering arms, and using a laser level tie wrapped to the wheel, and a mirror placed a couple meters away, reflecting back to a target on the wheel, set about checking bump steer. took an hour or so, removed front springs, but i eventually got NIL measurable bump steer over 2 inches bump to 2 inches droop.....whereas i could easily measure bump steer with the standard setup...
definately improved the feel on rougher roads.
With the 235 17 rsr fitted to the front, the car does now have a tendancy to tramline a little on rutted roads. Fitting std 15 fronts, that goes away, but you really notice the increased roll, washout, and tendancy not to go round corners, ...bit of a tradeoff i guess vs corner grip. I wonder if road 17 tyres would have less tendency, as some have reported track type tyres have more tendancy to tramline??
Making sure that bumpsteer was not causing an issue (or making it more noticeable), i fitted rose joints to the track control arms so i could space the arms up or down vs the steering arms, and using a laser level tie wrapped to the wheel, and a mirror placed a couple meters away, reflecting back to a target on the wheel, set about checking bump steer. took an hour or so, removed front springs, but i eventually got NIL measurable bump steer over 2 inches bump to 2 inches droop.....whereas i could easily measure bump steer with the standard setup...
definately improved the feel on rougher roads.
Edited by SteveSPG on Wednesday 20th February 12:41
Just noticed your epic Griff is now up for sale in the classifieds
http://www.pistonheads.com/classifieds/used-cars/t...
You have only just finished it.....???
http://www.pistonheads.com/classifieds/used-cars/t...
You have only just finished it.....???
griff waltzed through MOT earlier this week, popped it back in the garage at home, ready for some summer fun, then yesterday while i was overseas the builders turned up and finished bricking the drive entrance, so I cant get it out of my garage for a week till the concrete goes off......talk about bad planning..........
also fitted a rear ARB, which was a thicker one i picked up from one of the breakers, noticed the old wishbone mounts on lots of cars were bent, so i made up some to fit to mine, which were made from 4mm thick 40mm U channel, also made some new rose jointed arb fittings rather than the poly or rubber ones.
i ordered a stiffer front arb from coil springs, which is made to same specs as the 26mm front arb that tvr fitted to some cars.
running with no front arb, and a stiff rear arb certainly gives a slightly unusual handling characteristic at speed through corners, not terrible, but i do regret using my old front arb as a template to leave with the guys making the new one!
also fitted a rear ARB, which was a thicker one i picked up from one of the breakers, noticed the old wishbone mounts on lots of cars were bent, so i made up some to fit to mine, which were made from 4mm thick 40mm U channel, also made some new rose jointed arb fittings rather than the poly or rubber ones.
i ordered a stiffer front arb from coil springs, which is made to same specs as the 26mm front arb that tvr fitted to some cars.
running with no front arb, and a stiff rear arb certainly gives a slightly unusual handling characteristic at speed through corners, not terrible, but i do regret using my old front arb as a template to leave with the guys making the new one!
Edited by SteveSPG on Thursday 11th April 16:11
SteveSPG said:
a moment of boredom, the plans for "another build project" are looming, but ive decided to keep the griff anyway.
picked up a garage mate for the griff today...engine needs TLC, but paint is pretty good. interior renewed in leather a couple years back so looks pretty fresh, (*albeit a bit grubby as you can see from the bit i cleaned on the centre console) chassis spot on, is still on original shocks etc so those may get replaced
sound basis for some tinkering over the winter
Edited by SteveSPG on Saturday 11th May 21:05
Edited by SteveSPG on Saturday 11th May 21:12
V8BJC said:
Steve,
Tam looks great. Really like the colour combo.
Did ROS make you park them that way around to try and save some fuel money on the Griff?
Brian
one of the reasons i got THIS one was because i liked the colour......and it satiated my desire for a project....Tam looks great. Really like the colour combo.
Did ROS make you park them that way around to try and save some fuel money on the Griff?
Brian
Ros has been surprisingly supportive of the twin tvr garage.....though at some point i am sure it'll cost me.
She was less impressed when it meant i had to start both up Sunday morning though to get the griff out for the local meet....
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