Quaife Diff Fitting free play issue

[paulpolo]

I'm just fitting my Quaife diff and i've got to to the stage where I need to measure the freeplay so I can work out the thickness of the washer for the clutch side of the gearbox. Got the taper bearings fully seated on the diff and the races fully seated in the gearbox (clutch side without washer) and the 1mm washer behind the gearbox side race.
The problem is my freeplay is only coming out as 0.56mm on my digital dti, which is too small as their are no washers that size (0.56 + 0.3), i'm just wondering if there's anything else i need to consider or something i've done wrong as I can't think what it could be if everything is seated correctly.

[hayesey]

I;'d open it up again and make absolutely sure the bearing races are seated properly and as far back as they'll go.

Also make sure you're moving the diff as much as possible. 

[paulpolo]

Cheers Hayesey that's all I can think of really, i'll have another go, but I looked at the back of all the races and they seem as if they're right down. I'll double check the end float with another dti gauge too.

[paulpolo]

 I've taken the races out double checked gearbox side washer is 1mm, tapped them both back in and heard them seat down, checked they are squarely seated they all seem fine. Double checked by tapping the taper bearings down using the old bearing and they are fully down on the diff. The reading I get now is 0.68 so I guess I could order the 1mm washer for the clutch side bearing? No idea if that's the right thing to do

[paulpolo]

I have a spare atv gearbox that has a wrecked diff so I swapped the standard diff that got replaced by the quaife into the second gearbox and measured the diff end float as 1.4mm so the only difference between the two boxes (other than the casings) is the diff, is it possible the quaife diff is machined wrong? Maybe one of the bearing seats is too tall.
Anyway I've proved to myself I'm not going mad and I am measuring the play correctly.
Not sure whether I can just fit another 1mm washer clutch side as free play is 0.7mm on the quaife and put it back together. I would use the other box but it was full of metal shards from the destroyed diff and I'd rather it got rebuilt before I go to the effort of fitting it in the car

[hayesey]

I'm a bit stumped to be honest,  I've never actually fitted a quaife so haven't encountered this.  I've never had such issues with gemini or gripper diffs.

I know there are others on here who do have quaifes though, anyone care to chip in?

Are you saying that the reading is now 0.68mm so the total is 0.98mm?  If so then I'd just use 1mm as 0.02mm is near enough, you need to round up or down anyway as the spacers are only available in steps of 0.05mm.

[Yoof]

Bearings all the way home on the diff?

[paulpolo]

Yeah its got me stumped too, I'm pretty sure the bearings are all the way down on the diff, spent all saturday looking at them, I can't get my thinnest feeler gauge between the back of the bearing and the diff on either side, and they look seated. (I stupidly chipped one of the races and had to swap out that and the bearing which is why the freeplay figure has changed).

I can't think of anything else I can do, considering that when I put new bearings in my spare box with standard diff the free play measurement came out fine and I used the same tools/methods to put it all together and measure it.

Yeah the reading is 0.68mm so I think i'm going to order the 1mm washer and hope for the best.

[Jezza-7]

I had very similar problems when fitting mine, but unfortunately i cannot remember what my problem was.

I do remember getting similar readings though and thinking the smallest is 1mm and i was after a .7mm one.

I'll have a read through what i was writing down somewhere and see if it brings anything back.

Are you using the VW gearbox workshop manual?

[Jezza-7]

Just had a read and i remember why, i got the shim mixed up! I had the shim on the clutch side and was getting odd readings but my free play was only around .90mm + the .30mm and there wasn't a shim that small as they start from (i think) 1.40mm.

From the FAQ bit "Took the shim out and measured the other one that got mixed up. 1.00mm exact and then read the volkswagen workshop manual where it does state 1.00mm is the gearbox side"

I did have to jiggle and turn the diff about to get it sitting right though. I put a driveshaft flange on the gear side of the diff to push up evenly as well. It took quite a few times to get it setup though until i got the same readings, but i was just doing this on my garage floor. I also put a flange bolt into the clutch side of the diff and tightened it up so i could get an accurate reading as my DTI isn't the best but kept slipping and didn't have a long enough reach.

Have you got any pics of it sitting in the gearbox at all?

[paulpolo]

Cheers Jezza, I've definitely got the 1mm washer behind the gearbox side race.

I didn't take any pictures I'll have another go with the flanges in too and get some pics. I just clamped a bit of steel to the box and used my magnetic stand to hold the dti gauge so the pointer was on diff itself. I even took out the speedo drive in the clutch side gearbox casing as I thought it might have been limiting the movement of the diff but it didn't make any odds.

I'm just doing it on one of those black and decker folding woodworking benches, i'd say it's only marginally better than the floor!

[paulpolo]

Got some pics of how I was measuring the play (I tried measuring from both sides and it was the same):

[Jezza-7]

Thats exactly how mine was setup as well.

I followed this guide step by step, http://workshop-manuals.com/volkswagen/polo-mk3/power_transmission/5-speed_manual_gearbox_085/final_drive_differential_differential_lock/adjusting_differential/

just wonder if its worth taking it all apart and starting again. Did you torque all the bolts? As it says in this manual to only do 5.

[paulpolo]

I just tightened all the bolts slightly , I could try again with only five, i've already started over when I had to fit a whole new bearing after i chipped one of the races so bit reluctant to do that again.

The only other thing I can think of is maybe in the past someone has swapped the bellhousing off another box, which I guess means the whole lot is scrap because the casings have to be matched? The gearbox looks mint inside though so hopefully this isn't the case. Also is there a quick way I can tell the gearbox side is an ATV set of gears?

[hayesey]

you need to torque all the bolts up to their correct settings (including gearbox casing) or you're not going to get a true value.