Diff Question
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Discussion

Well_Fans

Original Poster:

4,193 posts

255 months

Saturday 5th December 2009
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While the guys at the dyno today were taking the wheels off to attach it to the hub dyno they noticed my drivers side rear wheel was "sticking" as though the handbrake was partially on while the other side rotated freely. Now it did move but not smoothly and a definite clunk could be heard from the diff. Diff's always been a little noisy at slow speeds but today it sounded much worse. Question is - is it likely to just need some friction modifier or is the fact its "sticking" on one side mean its going to need more thorough investigation?

Wolfracer

2,074 posts

237 months

Saturday 5th December 2009
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From responses I have seen over the last couple of years - "agricultural", " heavy duty drivetrain", " simple engineering" etc... I would not be overly concerned unless there are significantly different sounds or noises. The first time my diff clunked, I phoned the RAC! That's not to say there's nothing wrong, but I have come to expect some degree of noise, clunks, whirs and bangs - which are fine unless they change?

Bonnie and Clyde

11,701 posts

223 months

Saturday 5th December 2009
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I know i know nothing but if the diff is affecting the freedom of one wheel more than the other is that not going to screw up performance to an extent (be gentle)

doleboy

747 posts

248 months

Saturday 5th December 2009
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Depends on the noise. The occasional bang or clung at low speed whilst turning is often a sympton of needing some more diff modifier. However, to a certain degree you'd quite likely want the diff to lock up occasionaly to help lay down a pair of black lines, so it's a bit of a tightrope you walk.

Many people have had issues rectified by diff mod, but there are the occasional real problems.

What's the symptoms you've got?

Well_Fans

Original Poster:

4,193 posts

255 months

Saturday 5th December 2009
quotequote all
well yeah the guy running the dyno did say it could explain why my torque curve wasnt quite as smooth as I usually get and why I was down a bit on power. I was more concerned it may jam totally at speed, locking a wheel and sending me into a ditch.

Bonnie and Clyde

11,701 posts

223 months

Saturday 5th December 2009
quotequote all
Well_Fans said:
well yeah the guy running the dyno did say it could explain why my torque curve wasnt quite as smooth as I usually get and why I was down a bit on power. I was more concerned it may jam totally at speed, locking a wheel and sending me into a ditch.
Thats what i mean yikes

mfp4073

2,111 posts

205 months

Sunday 6th December 2009
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I would check the handbrake shoes first , drive the car a mile or so,then very carefully check the hub for heat if it's too hot you burn your fingers!!!! and the brake shoes are binding.If it's cold they are OK.
Start checking everything else for back-lash ect. Finally new diff oil.
I was going to say take it to a V/hall dealer as a last resort....maybe not!

Well_Fans

Original Poster:

4,193 posts

255 months

Sunday 6th December 2009
quotequote all
no obvious heat build up, checked when it came off dyno - that combined with clunk from diff made me pretty sure thats where the problem lay. I'll try add some friction modifier to the Royal Purple diff oil thats in my diff - not supposed to need it but if its as simple as that its a cheap fix. Just concerned its gonna be a bit more expensive to solve..

SimonV8ster

13,026 posts

259 months

Sunday 6th December 2009
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Mines clunking a bit at the minute so gonna try some friction modify too and hope it sorts it out.

I think the Royal purple stuff needs friction modifier after a short while even though it says it doesn't need it.

build394

503 posts

215 months

Sunday 6th December 2009
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my diff was clunking a bit even with royal purple in it. the last time i was down at the fish i ask them to put a couple of oz,s of friction modifier in and had no probs these few months. i was told all diffs are different, some need a small amount others need more.

SimonV8ster

13,026 posts

259 months

Sunday 6th December 2009
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Does anybody know whether its an easy job to do ? Is it accessible by jacking the rear up or do you needs ramps to do it ?

What I'm saying is - Is it a DIY job ??!!

Bonnie and Clyde

11,701 posts

223 months

Sunday 6th December 2009
quotequote all
SimonV8ster said:
Does anybody know whether its an easy job to do ? Is it accessible by jacking the rear up or do you needs ramps to do it ?

What I'm saying is - Is it a DIY job ??!!
You can get to it by jacking the rear of the car up but i'm not sure if you can drain it properly.

bigwheel

1,640 posts

245 months

Sunday 6th December 2009
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SimonV8ster said:
Does anybody know whether its an easy job to do ? Is it accessible by jacking the rear up or do you needs ramps to do it ?

What I'm saying is - Is it a DIY job ??!!


When I needed to do mine, parked on the crest of a downslope and plenty room to lie under the rear and undo the level plug (no fluid escape [downslope]) and add some friction modifier. No jacking required.

Lil' Red Rooster

85 posts

247 months

Sunday 6th December 2009
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Sorry Bob! hijack!! possible sale 3:7 diff with 2 way kaaz, may swap for standard diff + cash

Well_Fans

Original Poster:

4,193 posts

255 months

Monday 7th December 2009
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how much cash? I kinda fancied a 3.7 ratio if mines gubbed?

k15tox

1,680 posts

212 months

Monday 7th December 2009
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Lil' Red Rooster said:
Sorry Bob! hijack!! possible sale 3:7 diff with 2 way kaaz, may swap for standard diff + cash



if you dont go for this ive got 2nd dibs!!! if bob doesnt buy, PM me plese rooster.

FENTY

47 posts

209 months

Monday 7th December 2009
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Easy job to do, but easier if you can put it up on a four post lift and this guarentee you have the right amount in , because the fill level is to the top filler plug. This really is a ten minute job on a lift, any garage should do this for a crisp tenner

SimonV8ster

13,026 posts

259 months

Wednesday 16th December 2009
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Just had 2/3 of a bottle of friction modifier added to mine and all is sweet smile