Lotus Elan and Lotus Elan Plus 2 Forums

JonB wrote:Well, this is useful:

http://www.skf.com/binary/30-285048/TT08_024.pdf

Whirring noise - points to loose pinion bearing preload. Other readings suggest the handbrake might be dragging (I did adjust it prior to this test run) and so I will loosen that off slightly first as it is easy to get at. Pretty sure it's the diff though...

Thanks for sharing this!

Thanks from me too! It's a bit like reading a health-magazine though and how many times have I had a sinking feeling at a sudden horrible, mechanical, sound only to realize it is the car next to me!

Just wanted to update this thread.

When I took the car to Spyder to have the lower front suspension spindle repaired, Andy commented that the diff torque rods were the wrong way round. So this morning I swapped them over and they do fit better (bushes more square against the diff ears). I had wondered if the misalignment of the bushes was causing the hissing noise. Anyway after a short while messing around under the car I rolled it off the ramps and went for a test drive.

Result? Much improved. There is still a very slight hiss but it is nowhere near as intrusive - quiet enough that can ignore it. Yay!

So an update on this thread which is not terribly good news.

Having pulled engine and box out of the car for a seal refresh (it was all leaking oil like a sieve), I decided to try and "adjust" the pinion nut to attempt to correct the pinion bearing preload. I turned it no more than one or two flats clockwise using a socket and normal ratchet. I can say that the torque required wasn't too much - and I've read that in order to crush the tube ("collapsible spacer" one needs something crazy like 120 lb/ft, or so I read). Anyway.. the diff is now whining like a scolded toddler! So I think it is completely wrong now.

Obviously I need a plan and I'm thinking of asking a professional to sort it out. Any recommendations for someone who knows the Ford diffs on the South Coast (of England)? I recall Road & Race Transmissions was mentioned. Anyone else?

JonB wrote:. Any recommendations for someone who knows the Ford diffs on the South Coast (of England)? I recall Road & Race Transmissions was mentioned. Anyone else?

Al ....."promotor" on this forum will sort it out for you although not quite the South Coast.

JonB wrote:Obviously I need a plan and I'm thinking of asking a professional to sort it out

If you are keen and not in a hurry it is possible to DIY. They aren't as mysterious as they are made out to be if you have manual in hand. Apart from normal tools all you need is a large vernier micrometer to measure cap spread and a pinion torque measuring gauge available quite cheaply from www.bearingkits.co.uk

I?ve had a chat with R&R and will be getting it done next week, if I can get the diff out in time. No point messing about with it any more - do it right, do it once is the order of the day (or twice in this case).

OK, pulled the diff out - not too difficult this time round. It took about three hours. On checking it over, I can see that I turned the nut about 1.5 flats away from the marks I'd made and there is a bit of play in the shaft.

Lesson learned, and my advice to anyone trying to swap out the pinion seal or bearing without the right tools and/or experience is this: let a professional do it...

Quick update, after a proper struggle to get the newly overhauled diff back in place.

Problem solved. R&R seem to have set it up perfectly and there is little or no noise coming from the unit. Cost of overhaul was about ?250 and they did it while I waited (well, I went to Ikea for a few hours then picked the diff up on the way home).

Very happy (with the diff.. not so much with the rest of the car!)