Club 80-90 Forums

Winchweight wrote:Any comment from the gearbox guru (Aidan), because no one told us this before our recent TDi conversion?

I get the sense that it's not a definitive thing, more that some of the people who've had TDis fitted for a few years are maybe starting to get a few issues with long term wear & tear. Jed posted recently about needing to get his gearbox refurbed, and lloydy is looking to pull his gearbox for a service because he's found gear teeth in the oil.

All those road-drill square-wave torque impulses have to go somewhere.

Sean
Aidan has been talking for years about what he's been seeing in Diesel gearboxes esp. TDi ones.
In fact, some of the mods he offers and recommendations are because of it. I haven't got the oiler plate or the stiffener insert... yet.

Not just driving style unless you mean low rpm gearchanges and lugging about everywhere☆
All Up Weight; wheel and tyre size; diff ratio (above 543 an added risk) etc

Out of interest Keith what diff are you running?


☆Neil's going to come on now and say... '..no chance of you being accused of that'

There's others too Daniel...

A VVT turbo on an AAZ might transform it... with a suitable control system - even a manual one just for cruise.
You'd never get the tDi consumption though.

clift_d wrote:

Winchweight wrote:Any comment from the gearbox guru (Aidan), because no one told us this before our recent TDi conversion?

I get the sense that it's not a definitive thing, more that some of the people who've had TDis fitted for a few years are maybe starting to get a few issues with long term wear & tear. Jed posted recently about needing to get his gearbox refurbed, and lloydy is looking to pull his gearbox for a service because he's found gear teeth in the oil.

mine gets quite a easy life really (problem might be diesel related might not..), and chances are its not the r&p on mine... all guess work til it comes apart though.. I am fitting a dual mass flywheel this time, which should help the box a bit. they weren't fitted by vw to these engines for no reason, and i think ill take out the 6.17 and fit 5.43 funds depending as i obviously have to change the front diff too.. i do find with the 6.17 I'm in 4th at 30mph and pooling along under 2000rpm which probably doesn't help

If i had a jx id fit a intercooler and oil cooler

wolfbus.uk wrote:what does yours rev at doing 60mph Keith?

Mine does just over 70mph at just under 3000rpm.

HarryMann wrote:Not just driving style unless you mean low rpm gearchanges and lugging about everywhere☆
All Up Weight; wheel and tyre size; diff ratio (above 543 an added risk) etc

Out of interest Keith what diff are you running?


☆Neil's going to come on now and say... '..no chance of you being accused of that'

2wd for me.....

Cheers Keith that's pretty tall gearing, more like my 245 Volvo Auto than how I imagine a rugged 4x4.

Am I right thinking that the taller the gearing and the tyres the more strain on gearbox or is it the other way around? Running the JX I can feel the gearbox is not being strained or jerked in any way, also new Sachs clutch. Really smooth after Aiden's rebuild.

Driving gently would help any car but physics is physics and the TDI engine is surely producing levels of torque a syncro gearbox etc was not designed for, regardless of how you drive.

Bigger wheels and tyres add strain, from what I've heard the lower ratio r&p's like the 6.17 are weaker than the more normal 5.43, 4.86..

Bigger numerical ratio = lower gearing. In theory, lower gearing means less strain on the drivetrain but at the expense of higher engine rpm for a given speed, but the engine will be working lower down it's duty cycle i.e. spinning fast, as opposed to straining at low revs.
In a T3 transaxle lower gearing demands a smaller size pinion head (they oly have only 6 or 7 teeth in any case) because the casing puts a limit on the maximum diameter of the crownwheel that can be fitted.
The 6-tooth 6.16 pinion head really is quite tiny, more like something from a 1930's small car axle.

...and because of that the tooth profile is different Aidan and Rob tell me. The switch to a different meshing is the 5.8 and above. I was told this was to do with the cost but it could also be the 486 and 543 'cut' doesn't suit such small and therefore tightly curved pinion faces.

.... although the diffs are low geared (high ratio) to give good crawling, with big wheels and low intermediate ratios they turn out high geared in 3rd and 4th.

As Lloyd says.. first can end up as good as useless in day to day driving let alone G gear. Dual ratio is out of the question of course without a transfer box.

Dual range...its just a dream.
It might be possible to do with a flat 4, using a "sandwich" casing on the input shaft i.e. between clutch housing and diff (as per Subaru, suprisingly small gears and with synchromesh!)
With an inline there just wouldnt be the room.
I digress....

HarryMann wrote:.... although the diffs are low geared (high ratio) to give good crawling, with big wheels and low intermediate ratios they turn out high geared in 3rd and 4th.

As Lloyd says.. first can end up as good as useless in day to day driving let alone G gear. Dual ratio is out of the question of course without a transfer box.

I am coming around to 5.43... 1st gear for me is probably like others G gear. Literally gets you moving and you change up