Lsd Into Eb1 309 Box

[Mick309GtR1 0]

Hi folks,

 

I have been struggling with fitting a baby ZF Diff into my track 309 Gti. The first time I fitted it all seemed well. Great traction.

 

How ever all went wrong when I got it on track. When cornering hard right a very loud banging came from the box. It was savage...

 

So box out and diff out to see that the crown wheel bolts were hitting the box casing

 

So we ground off the ends of the bolts and put it all back together again.

 

Took it for a drive and the noise is still there all be it much better.

 

What have I done wrong. How could the diff be moving over so much.

 

If anyone has any ideas please let me know

 

I will be stripping it again tomorrow..

 

 

Thanks a million

 

Mick

[Mick309GtR1 0]

Ok done a bit of reading and it looks like I need to change the drive shaft????

 

 

Can anyone confirm?

 

 

Mick

[GTI6BOY 29]

If its the same as a BE3 box then you need to grind the piece of ali off the inside the diff housing, you also need to chop 10mm off the short drive shaft or use the inner piece off a 306 gti6 which is already 10mm shorter.

 

This is all in my BE3 box tho.

 

Also what do you mean by baby zf diff?

[Mick309GtR1 0]

If its the same as a BE3 box then you need to grind the piece of ali off the inside the diff housing, you also need to chop 10mm off the short drive shaft or use the inner piece off a 306 gti6 which is already 10mm shorter.

 

This is all in my BE3 box tho.

 

Also what do you mean by baby zf diff?

 

 

Hi and thanks for the info. So we pulled the shaft out and grinded 10mm of the end.... Measured the shaft lenth against the inside of the diff (or as much as you can when its in the car) and it seemed like it would be fine..... Down the road and turn hard right andthe noise is still there. Its much les but still there....

 

Question is do I grind more off and how much before I run the risk of the shaft popping out???

 

You also mentioned grinding the inside of the casing.... we did that too.... but can you clarify which bit you ground off???

 

I really appropriate your info as this is driving us nuts..

 

Cheers

 

Mick

 

O and Baby ZF....... thats what the rally boys here call it.... May be just a pet name....

[Mick309GtR1 0]

UPDATE:

 

Well its finally sorted

 

Tried to shorten the shaft but this fail too. My mate (jack1.9) bought a 309 shell which had an Mi16 in it at one stage and as part of the sale he got a drive shaft that was used for Mi16 with a ZF diff.... Result. Fitted it last night and its perfect.

 

So track day next Friday week cant wait..

 

Mick

[jack1.9 0]

Yeah Mick,

 

I'm really looking foward to the trip to the track too

 

 

just don't forget that shaft is coming back out the day after the track day

[andychalmers 0]

The Baby ZF is the nick name for the ZF Diff thats uses standard 306 shafts. These were I think used in the 306 S16.

Be carefull if cutting the drive shaft down as I would have thought your shaft still wont fit unless you add splines to the inner bit otherwise it wont go into the box any more.

I have a baby ZF, only just started using it, I measured the settings and its set to 150ft lb on each wheel. I took car for a test on fri, was awsome on the gravel, no understeer but on the tarmac it was horrible. Just wanted to zigzag or throw you off the road. Im going to ring skip brown now for a bit of info. Also I need to fit power steering as its far to hard to drive without it, just wantes to go in a straight line.

[philfingers 5]

Also I need to fit power steering as its far to hard to drive without it, just wantes to go in a straight line.

 

Sounds juts like a TranX on gravel settings. The preload and ramp angles essentially locking the diff up, so when you turn a corner the wheels both want to travel at the same speed and therefor go stright on (which is an issue driving the car to work at normal roads speeds in the wet!). On gravel it's not an issue as the car is generally a little more sideways and the loose surface allows the wheels to spin at the same speed.

Tho I have to admit to knowing sweet FA about the ZF it sounds like the same symtoms as i got from my TranX with heavy (fully interleaved) setting and 60/30 ramps

 

Phil

[andychalmers 0]

Sounds juts like a TranX on gravel settings.

 

It is but twice as bad, mine is 160ft lb setting on the Zf & most Tran X are 25 to 75ft lb.

 

Looks like im going to run the ZF on gravel & my tran X on tarmac.