diff clonk/ driveline shunt
Discussion
I just cant find out whats causing my driveline slack now... I have changed:
All CVs
wheel bearings
gearbox output bearing
rebuilt diff with new diff AND cw/p and bearings
Can a worn gearbox cause shunting? It occurs mostly around 1500 rpm driving slowly, not when cruising. I can probably smooth alot of it out with mapping... but I feel theres a mechanical slack somewhere...
anyone?
All CVs
wheel bearings
gearbox output bearing
rebuilt diff with new diff AND cw/p and bearings
Can a worn gearbox cause shunting? It occurs mostly around 1500 rpm driving slowly, not when cruising. I can probably smooth alot of it out with mapping... but I feel theres a mechanical slack somewhere...
anyone?
I was just thinking the same thing this evening,, is it the high ratios just not working well with the engine Rev combination then over time it just magnifies itself through the gearbox and drive train,, thus wear but not specifically in one area,,
Just slack, I've been very fortunate since becoming a Tvr owner to have driven some great Tvr's of other enthusiasts,
One or two including Ricards (Sheel) car and that's taught and I can't get it to shunt/knock,,, I'm sure it's been masked by these components for years and only now on my car anyway is it becoming obvious,, I don't get shunting that's detectable from the ign/ fuelling system as I'm on a very smooth Mbe Ecu so I've largely done away with the route cause,, but at the revs you've just mentioned Ole, it's still possible for me to get this imbalance between the engine and gearbox and axle,, and get some slack getting taken up and the knocks that go with it.
Par for the course on some cars, no issue at all on others? Luck of the draw,, the reality is when my cars under load as when going fast the drive train is sweet and very direct and solid and silent!
I've done drive shafts and diff mounts, made no difference, prop UJ's seem to have no play but I will change them as a routine fix, then it's into the internals but I think I could go on and get nowhere!
Is it one of those " they all do that sir" !
There must be an answer though!
Just slack, I've been very fortunate since becoming a Tvr owner to have driven some great Tvr's of other enthusiasts,
One or two including Ricards (Sheel) car and that's taught and I can't get it to shunt/knock,,, I'm sure it's been masked by these components for years and only now on my car anyway is it becoming obvious,, I don't get shunting that's detectable from the ign/ fuelling system as I'm on a very smooth Mbe Ecu so I've largely done away with the route cause,, but at the revs you've just mentioned Ole, it's still possible for me to get this imbalance between the engine and gearbox and axle,, and get some slack getting taken up and the knocks that go with it.
Par for the course on some cars, no issue at all on others? Luck of the draw,, the reality is when my cars under load as when going fast the drive train is sweet and very direct and solid and silent!
I've done drive shafts and diff mounts, made no difference, prop UJ's seem to have no play but I will change them as a routine fix, then it's into the internals but I think I could go on and get nowhere!
Is it one of those " they all do that sir" !
There must be an answer though!
I only find the drive line slack a problem when you have a lurching/snatching car or stiff throttle etc other than that 
all the diffs have slack Peter I would say the GKN and BTR both share that trait but in saying this the diffs close proximity to the driver does us no favours at all 
all the diffs have slack Peter I would say the GKN and BTR both share that trait but in saying this the diffs close proximity to the driver does us no favours at all Sardonicus said:
I only find the drive line slack a problem when you have a lurching/snatching car or stiff throttle etc other than that all the diffs have slack Peter I would say the GKN and BTR both share that trait but in saying this the diffs close proximity to the driver does us no favours at all
^^^THIS^^^ all the diffs have slack Peter I would say the GKN and BTR both share that trait but in saying this the diffs close proximity to the driver does us no favours at all And what you need (if you have an after market ECU) to eliminate the lurching/snatching is closed loop throttle
phazed said:
Mine has always been a bit clunky at about 1500 rpm and the whole drive system has only done 43,000 miles.
I have renewed the CV joints, had the diff overhauled and checked the prop shaft UJs, to no avail.
I think it probably is in most cases a bit of TADTS!
My car was meant to be having its CV joints changed yesterday, but called it off because I am struggling to find GKN CV joints at anywhere near sensible money. I have renewed the CV joints, had the diff overhauled and checked the prop shaft UJs, to no avail.
I think it probably is in most cases a bit of TADTS!
Which make and part number did you guys buy, and what do you think about them having fitted them, please?
Barreti said:
Quite surprised to here this QBEE, what do you mean by sensible prices?
There are CV joint details in the Griffith Parts List
The standard TVR parts merchants want close to £100 per CV joint, inc boots.There are CV joint details in the Griffith Parts List
Prolinx want £70, plus boots etc.
My local car parts place wants to supply me new (not recon) Shaft Tech ones at £30 each, my only issue is not knowing if this gift horse has dodgy teeth.
Let's face it, they are simply 1990 Sierra Cosworth parts, the only issue is strength and quality of the replacements, as we are putting a lot more than Sierra Cosworth torque through them.
Opinions, guys?
Sardonicus said:
OleVix said:
my diff is a new quaife.... maybe i'll change the prop UJ, its the last thing before changing gearbox 
That amount of slack in the prop would be obvious and if you didnt spot it before your arse needs kicking 
and it wont be the box 
I replaced my diff bushes, gearbox mounts and had a full propshaft refurb, the drive line feels very solid, reduced the effects of shunting massively and made the gear selection much smoother, particularly reverse.
There was no clonking but decided that at 17 years old and 39k miles, it was overdue
There was no clonking but decided that at 17 years old and 39k miles, it was overdue
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