Whining noise from rear end

[milothedog]

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Dave M wrote:

nib wrote:

Dave,do you know how easy it is to sort the backlash out,the reason I ask is that I have a nice and quiet diff in the shed that has a bit too much backlash.

Mark

Sorry Mark I dont, Ive took a chance on a s/h diff thats supposed to be good, was hoping to get my diff sorted but dont know whats involved, perhaps someone on the forum will enlighten us.

Dave

Sorry to be a kill joy chap's but it's not really a DIY mechanic's job you will need a DTI gauge and some engineers blue for a start and a source of reference to set it so you get the correct meshing pattern on the gears. it's the meshing of the crown wheel & Pinion that determines the amount of backlash but also allows it to run quietly as the contact area has to be in the correct position on the gear teeth faces. A job best let to the specialist I'm afraid.

Hope that answers your question, I think there is a previous post about rebuilding a Diff from Don Kennedy.

Ian.

[richardthestag]

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Dave M wrote:

All this talk of changing diffs, Ive got mine to do as the backlash (I think) in mine is causing clunking noises. Can the diff be dropped out with the car still on its wheels? The reason I ask is because I have a set of hydraulic ramps and getting the car in the air whilst still on its wheels is easy.

Dave

Yay I have hydraulic ramps (see avatar <&ltalso and they are the best thing eva...

As a seasoned diff removal expert i'd would;

Get it on ramps but not too high then support the back end of the car with axle stands on the rear end of the sills. lower ramps and leave wheels dangling.

Getting the exhaust off is the biggest pain, use plenty of wd40 into the joints and it should free up. You will need everthing aft of the silencers off the car.

Undo the rear prop uj. I have a lump of wood that I use to wedge the prop and silencers tight to the bottom of the car to keep them out of the way.

Undo one end of the hand brake cable

Undo both inner drive shaft yokes from the diff and pull the inner end off the splines. A latex glove over the exposed splines on the carshould keep things grit free.

Put a trolley jack under the trailing edge of the diff and support it while you undo the two small nuts that hold the diff rear mounting to the underside of the car.

Lower the jack slightly to allow access to the four bolts that secure the nose to the diff. I have a reinforced nose fitted which makes access to the top bolt tight. I have a shortened spanner to do the top bolt!!

When all four bolts are undone lower jack as far as it will go if not done already:Pwhile still supporting the diff and move the diff backwards and off the nose quill shaft splines, it might need a couple of swift taps from your rubber hammer. You will need to lower the trolley jack as the diff moves towards the rear and off the splines.

You might fancy using your hydraulic ramps assy in some way to assist. I have crushed thumbs and split finger nails trying to stop the diff falling 2" to the floor. More recently Darwinian evolution has made me scatter lumps of wood on the floor to soften the blow should the diff not like the trolley jack and I am reluctant to prevent it.:dude:

The diff will probably also try to tip forwards and attempt to deploy its contents all over the garage floor. Redeploying one of the lumps of wood from the floor to support the front of the diff on the now lowered trolley jack saves you having to reach for the kitty litter.

With the diff off you may find that when you spin the quill shaft from the prop end that it grates against the housing. This = buggered nose bearing. Undo four big bolts and remove nose from subframe arms.

I always replace the oil seal in the front of the diff while it is apart.

I agree with what they ^^^ say, eliminating backlash is a pro job.

[Rubce]

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Dave M wrote:

All this talk of changing diffs, Ive got mine to do as the backlash (I think) in mine is causing clunking noises. Can the diff be dropped out with the car still on its wheels? The reason I ask is because I have a set of hydraulic ramps and getting the car in the air whilst still on its wheels is easy.

Dave

Dave

I reckon its as follows:-

reverse car onto ramps and chock
disconnect both drive shafts from diff
place jack under diff
place oil catch tray unde front of diff
remove two nuts that secure diff to vertical supporting rods
remove four setscrews holding diff to front extension housing
lower jack slowly
pull diff backwards by hand to allow it to slide off the front extension
remove diff from jack and hey presto

I reckon you won't have to remove any of the exhaust system as I managed to do the above process on my donor car last year.

Hope that helps

Bruce

[adieturner]

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It certainly sounds like the Crownwheel & Pinion are your noise source. Good news is that it will probably run forever like that!

There's only one solution, have it rebuilt and the gears set up correctly. Bad news is that many of the gears for sale are complete crap and it could be just as bad afterwards with new gears.

If anyone has a "bad" new pair I'd be happy to do a little measuring from the gearform and see if they can be improved with a clever bit of grinding.



Adie

[Rubce]

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I have what I believe is a 1:3.45 diff off the donor car which I don't remember making any noise. Might clean that up, fit a new oil seal and rear gasket and pop that on the car.

Can anyone tell me where abouts on the casing the serial no. is likely to be?

Thanks

Bruce

[DJT]

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Rubce wrote:

I have what I believe is a 1:3.45 diff off the donor car which I don't remember making any noise. Might clean that up, fit a new oil seal and rear gasket and pop that on the car.

Can anyone tell me where abouts on the casing the serial no. is likely to be?

Thanks

Bruce

On the flat undersurface, Bruce. It is usually quite faint and may only be visible after cleaning with a wire brush and rubbing with an oily rag.

Dave

[Dave M]

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Thanks for the info guys and sorry for semi hijacking your post Bruce, next question how do you tell what ratio a diff is?

Richardthestag thanks for the explanation, Ive removed my diff before just as you explained, exhaust is off anyway asI need to swop the prop as the new CV jointed one I recently fitted is not balanced, I would just prefer to do it with the car on ramps rather than axle stands though.

Dave

[Andy Rundell]

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Dave M wrote:

Thanks for the info guys and sorry for semi hijacking your post Bruce, next question how do you tell what ratio a diff is?

rotate the drive shaft by exactly 1 revolution and count the number of turns you get on the prop flange

...........Andy

[flying farmer]

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If you have a quiet diff with lots of backlash the odds are it is the bronze thrust washers behind the small gears that are mounted on the pin through the diff. The pin is held in place with a small roll pin. Knock this out and the pin can be withdrawn without dismantling the diff. If the gap between the thrust washer and the back of the gears is measured, then this thickness added to the washer, new ones can be ordered. I have had to do this twice on the TR, though the diff is coming up to having done 250,000 miles and it is starting to whine on the overrun, it may require a bit more attention next year:?

[nib]

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Thanks for the replies and sorry for butting in on your thread Bruce.

Mark

[Rubce]

Hi All

Due to various family reasons I have not had the opportunity to investigate this further to-date. Hopefully I will get time to clean up my spare diff this weekend in case I require it.

I have clarified that I already have the 85/140 oil in the diff fitted to the car so that idea won't help on this occasion.

Before I swap the diff out I want to see if simply replacing the voided poly mounting bushes with rubber ones makes a significant improvement. Is it possible to swap the mounting bushes without having to disconnect the diff from the driveshafts or the front extension?

Regards

Bruce

[Rubce]

Nobody tried it?

Bruce

Hi All

Is it possible to swap the mounting bushes without having to disconnect the diff from the driveshafts or the front extension?[/B]

Regards

Bruce

[Kevin Garrod]

Sorry, Er yes I think it is possible.