Hi, im new here and need advice.

im building a Velocity XT using the running gear from a J plate Sierra DOHC ( not using engine ).

We came to bolt up the diff and found a problem.

looking from the rear of the car towards the front... the left top mounting flang seems wrong. On our diff, the left hold mount is further away from the centre than the right hand top mount, so on the car, the bolt flang needs to be further left.

Has anyone else found this? Is it a that i have a strange diff ( although i have looked at 3 diffs from Sierras and they all have the same mounting difference )

help! thanks!

Ian

I'm not entirely sure I unnderstand your problem, but can offer/ask the following:

Does the dif physically fit between the mounting plates? There are 2 (well actually 3) sizes of fod dif, 7" is common sierra though 7.5" is on some cars + granada, + cosworth. (9" is ford motorsport i gather) The size is the diamter of the cwp but also correclates to the distance across the top of the dif where the bolt/holes are if that makes sense.

Also ford sierra rear ends are so that the drive shafts are unequal lengths and the dif will sit slightly to one side and appear off centre; the input from the prop will be central, but the driveshaft flanges lobsided.

Doe this help at all?

If not can you get a picture on here for us?

Ned.

On mine the mounting bolt holes are equi-distant from the centre of the flange.

The drive-shaft flanges are differently spaced but the mount holes definately aren't.

All the MKs I've seen are centrally mounted too.

HTH,

James

EDIT: See, I agree with Ned!

[Edited on 12/10/04 by James]

Hi,

cant get any pics at the moment, but ill try and explain better...

1) im not sure what size diff it is, but its the diff fitted to DOHC sierras.
2) the diff will fit between the bottom two mounts, but not the top two. the bottom two mounts, and the top right hand mount all bot up, the the top left seems to be positioned in the wrong place...

if you look at this picure from the build manual..

http://www.luegosportscars.com/cars/velocity/build%20manual/section%201/pics/image020.jpg

you can see that the top two mounts are equi-distant from the centre point, and although the diff is lop-sided interms of drive shafts, the top mounting points seem to be equi-distant from the midpoint.

this is not the case with our diff. the left top mount is further left..

i dont mind cutting the flange off and re-welding it, but wondered if anyone else has come across this, or have we got the wrong diff???

thanks for the help so far ned,

ian

as james says, the dif bolt holes should be symetrical about hte centre of the dif and chassis, if this isn't the case it's most likely the bracket has been welded in the wrong place, i'd suggest calling luego if you're that worried about it, otherwise I'd chop it off and reposition. photo would be good to confirm before you do anything hasty though

Ian,
There is a difference between certain Diffs and you are correct in your observation about the 1/2" wider (assymetrical) top bolt flange. I believe the common fix is to cut off the additional or unwanted 1/2" - don't ask me how to achieve it with precision though.

Yea!

not going mad then!!!

ok. our idea was to cut the flange off with a dremel ( very slow i know, but very accurate ) , bolt the diff up to the 3 correct flanges and then bolt the cutt off one to the diff. Where ever it rests against the chassis, weld it on.

not sure if that will be ok though! :-)

Ian.

Don't bother with a Dremel, it will take hours and god knows how many cutting disks!

You can get very thin cutting disks for angle grinders (0.8mm) that will slice through that in no time flat. Even a hacksaw would be better IMO.

are they those "plasma discs" i have seen advertised?

do you know where i can get them from, not sure B&Q will stock them, and as for Halfrauds.....

Gotta agree with Mike there.

Although if your chassis is powder coated then it might be worth avoiding the hacksaw option as I find you tend to scratch the surrounding area with it.

HTH,
James

quote:

---

Originally posted by saigonij
are they those "plasma discs" i have seen advertised?

do you know where i can get them from, not sure B&Q will stock them, and as for Halfrauds.....

---

as an alternative, if the lug is 1/2" too far out, can you not pack it out with washers or a small bit of tube/block with a hole in as a spacer and just bolt all the way through?

Ned.

no,

the flange is about 1/2 inch too far in to the centre. it need to be cut off and posisitoned 1/2 inch to the left, further away from the diff.

i found those discs on MachineMart. cheap too. have to get some.

thanks for all the help.

fair enough.

those thin discs are brilliant btw, should be able to keep it nice and neat.

Ned.

thanks to all .

:-)

this is the diff in the indy, if it helps

tom

try again

it's gotta work this time!
Rescued attachment 2004_0503stoe.jpg

hello there i too have used the dohc diff from a sierra and yes you are not going mad i found that the drive flange was central to the bottom two brackets but the top two brackets were off set to the left ( looking from the rear of the diff) by 20mm
i moved one bracket and made a spacer for the other side
hope this helps dave

I had exactly the same problem when i came across this with my XT. I used the diff from a 2 Ltr DOHC also, i got around it by bolting up the bottom then used a rubber mallet to reshape the top left mount, believe it or not it will fit. It took a bit of fiddling though but no cutting, grinding needed, see photo attached Shaywez

glad im not going mad!

the diff from the DOHC looks bigger / meatier than the earlier ones, or is it just my imagination?

was there anything else that you had problems with during your build that would be good to know about?

thanks again to all that helped.

Ian