Knock, knock.....
Discussion
I have a cross-flow, live axle with 20,000 miles on the clock. Yesterday, under acceleration, I started to get a knocking sound from the rear of the car the frequency and volume of which increased with the speed. When I eased off, it virtually disappeared. It's obviously coming from something rotating, and just as obviously it's coming from the live axle. I'm going to take it apart this week-end, but before I do, has anyone else experienced this problem, and if so, can you give me any guidance as to what it might be?
Well, got the UJ's all checked out and freed up, but have now established that the problem is with the half shafts which have separated from their bearings, allowing the rear wheels to float in and out. Have new bearings ordered, but has anyone else dealt with this problem ? Will I need to shim between the shaft and bearing or can I rely on a press fit ? Would be grateful for any advice on this.
Sbend said:
Well, got the UJ's all checked out and freed up, but have now established that the problem is with the half shafts which have separated from their bearings, allowing the rear wheels to float in and out. Have new bearings ordered, but has anyone else dealt with this problem ? Will I need to shim between the shaft and bearing or can I rely on a press fit ? Would be grateful for any advice on this.
HiStarted reading your post and you answered before I could.
End float on a Marina/Ital axle: about as common as seagulls around a bag of chips.
Or Flies round s**t etc
There are a number of ways to cure this, I'm in the final throws of repairing mine.
1) and seems the most popular, also the most complicated and expensive is to replace the axle with one from an Ford Escort. The Escort axle was used in the Caterham until the new supply dried up and Caterham went over to the lighter and inferior Ital unit. Changing to the Escort unit involves a complete new case, shafts, diff, LSD etc new brackets welding on the case, modifications to the tunnel as the diff case is larger, replacement wheels as the PCD is different. Benefit is that the escort axle is supposedly stronger, but still has inherent problems. Bits are more readily available for the ford unit. Assuming you are fitting an LSD you'll be spending well over £1400 on this (inc wheels) but you might get some money back on the old unit
2) There is a company who manufacturers an upgrade kit, replacing the bearings and carrier, hub and shafts. PM me for a discussion on this outfit.
3) Replacement bearings and shimming the set up. The cheapest option and possibly the simplest. The bearings are only located on the shafts by interference fit. There's nothing to stop the shaft moving in and out of the bearing. Remember the Ital had about 50bhp to cope with, you are probably putting more than twice that through it. (The axle will apparently cope with about 170bhp but not without strengthening. The bearing is a press fit in the axle case and held in place by the retaining plate. There is a machined step on the shaft but from the factory, the bearing wasn't supposed to sit on that machined step. BL Engineering at it's most entertaining.
I bought a full bearing/seals/shim kit from James Whiting a well respected guru on all things Seven, who talked me through various options and methods of repair.
As above, I'm happy to discuss this more, phone might be easier than the one fingered typer.....
To add, I've just tried to email you but your profile won't allow emails. Drop me a line with your number and I'll text mine back.
BTW way abouts in the UK are you
Regards
Tony H
Edited by Skyedriver on Friday 30th September 22:32
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