Diff bolts.

se7ensport · Post by **se7ensport** » Wed May 30, 2007 11:02 am

Having read Rob's info on the green car I think I may have the wrong size diff bolts, occasionally I get a clonk at the back, it's usually caused when I go from reverse to forward or forward to reverse, otherwise I can dump the clutch has hard as I like and nothing happens.

What size should they be? Are they easy to change i.e. does the diff require supporting or can you push the old bolts out with the new one?

Cheers

Alex

alecmartin19 · Post by **alecmartin19** » Wed May 30, 2007 12:08 pm

this sounds like either the bolts like you said or possibly a worn UJ or backlash in the diff itself.

what kind of diff have you got? is it sierra or escort live axle? my escort live axle has threaded holes in the nose of the diff so you can only fit one size of bolt. let me know and i'll try and help.

alecmartin19 · Post by **alecmartin19** » Wed May 30, 2007 12:10 pm

also, do you get a clunk when you back off the throttle or when you put it back on again or is the engine too loud to hear that?

stylussprinter · Post by **stylussprinter** » Wed May 30, 2007 12:51 pm

se7ensport wrote:Having read Rob's info on the green car I think I may have the wrong size diff bolts, occasionally I get a clonk at the back, it's usually caused when I go from reverse to forward or forward to reverse, otherwise I can dump the clutch has hard as I like and nothing happens.

What size should they be? Are they easy to change i.e. does the diff require supporting or can you push the old bolts out with the new one?

Cheers

Alex

I think you're refering to the threaded rod around 10 inches long(two of them)that secure the Seira diff to the dedion frame

Originally P.Powell used 12mm but Tim fits and suggests others upgrade to 1/2 inch which will fit . Another upgrade around the symptom you describe on the dedion axle is to steady the frame further but you need to talk to Tim as it's his own mod' and I've no experience of it. I said I'd change them on the green car but didn't as they appeared to be very solid so possibly were 1/2 inch

As for how easy , you would need the car in the air then support the diff ---- then knock them out with a bolt .
Rob(you do have a dedion don't you

)

se7ensport · Post by **se7ensport** » Wed May 30, 2007 12:58 pm

Hi Alec

No clunk on lift off and there is minimal play in the diff & UJ joints.

It's the de-dion set up, and the bolts run through the diff rather than bolt into it. The clunk only seems to happen when the diff is made to run in the opposite direction and once the clunk has happen you can't repeat it without going in the other direction. I'm clinging to the idea of diff bolts as they have to be the cheapest and quickest fix

re: loudness, I'm pleasantly surprised and can actually hear stuff other than the exhaust note, it's sounds great but doesn't give me ear ache, unlike previous cars!

Schrodinger · Post by **Schrodinger** » Wed May 30, 2007 4:41 pm

If that a sierra dif then that should have threaded holes on the drive plate so you shouldn't be able to put the wrong size in, unless somebody has put smaller bolts through with nuts on or drilled them out at some stage.

stylussprinter · Post by **stylussprinter** » Wed May 30, 2007 4:54 pm

Schrodinger wrote:If that a sierra dif then that should have threaded holes on the drive plate so you shouldn't be able to put the wrong size in, unless somebody has put smaller bolts through with nuts on or drilled them out at some stage.

Alex is refering to the long threaded rod , two of them , that hold the diff' casting onto the dedion frame. Not the diff' flange.

Rob.

se7ensport · Post by **se7ensport** » Wed May 30, 2007 4:57 pm

stylussprinter wrote:
se7ensport wrote:Having read Rob's info on the green car I think I may have the wrong size diff bolts, occasionally I get a clonk at the back, it's usually caused when I go from reverse to forward or forward to reverse, otherwise I can dump the clutch has hard as I like and nothing happens.

What size should they be? Are they easy to change i.e. does the diff require supporting or can you push the old bolts out with the new one?

Cheers

Alex
I think you're refering to the threaded rod around 10 inches long(two of them)that secure the Seira diff to the dedion frame Originally P.Powell used 12mm but Tim fits and suggests others upgrade to 1/2 inch which will fit . Another upgrade around the symptom you describe on the dedion axle is to steady the frame further but you need to talk to Tim as it's his own mod' and I've no experience of it. I said I'd change them on the green car but didn't as they appeared to be very solid so possibly were 1/2 inch
As for how easy , you would need the car in the air then support the diff ---- then knock them out with a bolt .
Rob(you do have a dedion don't you )

Rob

Thats the ones, as it's just threaded rod I'll pick some 1/2 inch up and give it a go.

Schroder

Where the flange mounts it uses the original bolts, it's actually the whole diff that I think it moving.

Cheers All

Alex

se7ensport · Post by **se7ensport** » Sun Jun 03, 2007 9:51 pm

Another sod of a job to fit, should have taken 30mins but took 3 hours

The holes between the diff and the mount were a very tight fit requiring the bar to be wound in, with only a small amount of movement availble for the spanner it was really frustrating.

Made a real difference, no more loud clonks, it's also made down shifting smoother (i didn't notice the play originally, but I have the difference!).

clubstylus

Diff bolts.

Diff bolts.

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sierra diff

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1/2" bolts