Rear axel rumblings

[johnbirmingham]

I guess this must have been covered before but as a rookie I've not seen it . The rythmical rumble became noticable about 1k miles ago ( I'm a bit deaf ) but has now become worrying . A long standing weep from the pinion seal set me off opening a can of worms/Pandora's box ! There is a fair bit of backlash so out came the diff. unit to play with on the bench...the fun begins.
1 The pinion bearing seems OK but the preload measures only about 5 lb/in. Should one re-preload a bedded in bearing?
2 If there is no need to mess with the pinion may one take it's hieght for granted and take up the backlash at the crownwheel ? Size for size the pinion should get the most wear implying that the big 'un needs to close ranks.
Thankfully there's no other signs of wear except a bit at the halfshaft splines...so why the rumble ? You've guessed it...wheel bearings (could we have a smiley face in RED ,please ?) There were no oil leaks and they seemed OK on the car but on the bench they sound bad. Now the fun really begins...retaining collars !! I made up a long tubular tool like in the manual...couldn't budge 'em . Have now cut a groove down the collars with a narrow chipping chisel to weaken them...still no joy. Heat looks out of the question.Impact while under extreme pressure(big 'ammer)..no luck.Have I missed a trick ? It's a '72 car-did they do something devious we've not been told about ? The "point of no return" is passed.Any sugestions ? John.

[Phil Nottingham]

Always eliminate the easy first and read the workshop manual!

I have never built up a back axle before but the manual gives detailed set-up instructions. The best way would be to return everthything back to what it was or take to a specialist. I would risk adjusting the preload but the bearing will fail eventually. The backlash can become tremendous before anything needs doing

Wheel bearing do often fail gradually or suddenly without warning or leaks - Ii have have several go now. The noise they may is very characteristic on any car and once heard never forgot

Again the manual gives instructions - a special tool can be used to remove the collar which must be renewed as it holds the hub on and is very tight and a press is best with a load up to 20 Tons.

To refit the old trick of freezing the hub and heating the ring can be used with long length of scaffold tube and a sledge hammer but its still best tio press it back not forgetting to put on the back anchor plate first

Beware chiseling the ring off as nicks in the axle will cause stress points leading to the shaft shearing. Heating it red hot will expand it sufficient to move it but again it could cause damage to the shaft

Good luck

[jlalexander]

Hi John,
the bearing preload for your diff is crucial; the danger is not to damage the bearing but to set the bevel pinion to close to the crownwheel; if you never did the job before I would warn you not to try to do it. It's really a specialist job. The main reason is that your bevel pinion and the crownwheel are allready mated together, and if you disturb the contact point between the two, you will end up with a worth noise. The bevel pinion and crownwheel of the P5B have been used till very late on the Range Rover: same ratio and same part number; if they need replacing they should not be hard to locate from the numerous classic landrover parts suppliers. To have your diff refurbished/adjusted I would suggest a firm in Crawley called Auto Europe (01293862606) Maurice who runs it is a very knowledgable man and a real expert for diff and manual gearboxes ; I have used his services for 15 years without any problems. Regarding the hub bearing, Phil gave you a very sensible advice: no heat no chisel !!!!! I have the special tool to do the job, and I can tell you that the drawing in the WS manual is a bit of understatement regarding its weight and size ; even with that tool I use a 3/4 drive socket and a very serious prybar to undo the collar. To fit the new one instead of using the tool has a ram as suggested by the WS manual (this method is not very technical and a bit rough) I use the tool as a medium between an hydraulic press and the collar. To fit the new collar fully home, you cut the old collar vertically on all its length and use it as a driver; when the new collar is located fully home you will understand why the old one had to be cut, because even like this, it does not come out that easilly. The press must be a 20 tons one.

[Phil Nottingham]

I always wondered whether the somewhat Heath-Robinson tool was as effective as a proper heavy duty press - it seems like it only just works and I do not the idea of using it as a ram to batter the new ring into submission.

As usual the WS manual does not give the "true life" situation

[johnbirmingham]

Thanks Phil & J.L.A.
I had eliminated heat as the collar is down an awkward hole to apply it and fears for the shaft's temper.In desparation I chiselled a second deep groove down it and re applied my home made puller ( it is a scaffold pole with a thick six hole plate on one end & a heavy ex WD extractor welded on the other). With my full weight on a 2 ft.lever it finally shifted with an awful bang and was still very tight for a full inch or more.On inspection there was still over 1mm left at the bottom of my grooves and almost an inch along the length .The shaft was safe and it is reassuring to find that effectively half a collar was enough to hold the wheel on !!
I share your missgivings re. reassembly as per the book,chaps.Using the old collar, split, is an inspiration!Thanks. I can rig up a makeshift press using lorry size bottle jacks but am pondering drawing it on with six long "Unbrako's" via a plate across the blunt end of the shaft as an easier option.This may not be quick enough to benefit from heating the collar though.
Re. the pinion,I was at fault measuring the pre load - there is none left at all. (Clever-clogs was working against the crownwheel : I may well put it back unmolested.
Thanks again ...any further comments welcome...John.

[jlalexander]

John, I forgot to mention that I always put a little brass billet between the pushing end of the extractor and the shaft splined end for obvious reasons. I think that you could find a friendly workshop around with a hydraulic press, because as well as the bangy way out, the way in is also a bit rock & roll noisy, and only a proper press will push the collar fully home. The working bridge of a press can be lowered down to the ground. The wheel side of the shaft must be on a thick piece of wood . The bespoke made press can bring you to some funny situation ( I'm talking by experience, with a certain number of customers bringing me their Heath-Robinson like P5 halft shafts states, including severall engineers, I shall not mention names, hello G... if you're around). Good luck

[johnbirmingham]

Thanks JLA,I had gone ahead before getting your post so must now check that the splines will still slide in OK.I got to pondering the force I applied to shift the collar as my set-up gave a ratio of about 1500:1; I cant believe it ! I'll let you know if the shaft ends are at all upset . On to the pinion : my end is not like the manual (issue 1...was there an issue 2 ?) Theres no detachable seal housing so some butchery was needed to get the worn seal out.It was leather ! It was also a surprise to find no shims as per book,just the 2 thick washers.That settles any thought of messing with the preload. I've had the car from nearly new so I'm sure no one's been at it before.Like you say Phil,the WS book needs to be taken with a pinch of salt.Now to find a pressman I think.Regards , John.

[jlalexander]

John, to remove an oil seal there is a special tool supplied by many Tool makes; one between them is Tengtools (Seal Remover Tool part n°AT145) it's worth £ 9.80. This avoids butchering. About the lack of shims for your bearing pre load, it could well be that the thickness of the "washer for shim"was OK.the shims are fitted only if requested. I would be very surprised if your diff has no shim for pinion position.Do not over grease the bearings if you replace them. If you want to check the total backlash of prop-diff-half shaft you will find the operation described in the P4 workshop manual.JL

[Phil Nottingham]

Very late P5B diffs made under the BL regime were cheapened and did not have the removeable seal housing. BL never updated the WS manuals after about 1970!

[johnbirmingham]

Mission acomplished! .But,Phil&JLA,you were quite right,it is seriously pushing the limits for the home mechanic.I failed to find a professional to tackle it so rigged up a press using four long 1"dia.rods secured to 1 1/2"steel plates at each end.My bottle jack has a 2 1/2"dia. ram so "robust" is the word!Engineering books say 3-4 thou interferance for a force fit to a 1 1/2"shaft but the new collars supplied by J.W.were nearer 8 thou.Perhaps it would be fairer to say my half shafts were a bit on the fat side .I got the bearings on seperately to ease the load and was glad I did...using my puller loaded with additional weights until I could barely lift it, I struggled to bump them down.The collars were pre heated but by the time the press was assembled round the job they needed warming again in situ.The jack seemed to push the collar on but it began to tear the end off the puller I had used as an intermediary, before it got fully home.Welding reinforcement needed.With an extra long handle I managed to pump it right home after much sweat.
On the car it was a relief to see the oil thrower lip lined up nicely in the groove with the 3 holes and to note the brake shoes tracking as before.Oh,joy!
As for the pinion bearings,I carefully stoned a thou off the washers which introduced 2-3 ft.lb.of pre load.I'll await early bearing failure!That leather seal was an earlier type says J.W.,and was considered superior.He could only supply the latest sort!
I will never try this job again,but if the new bearings last as long as the old , I may never need to.
Now I think I'll take another look at that starter motor.....
Regards, John.

[Phil Nottingham]

Thanks for the update - I have just replaced the original leather pinion seal on my 64 Coupe. I was disappointed to find the "new" one I had kept for mnay years was also leather as I thought it inferior to the later Neoprene type!

I replaced a rear wheel bearing seal on my P2 which is identical to the P4/P5 set up with a new old stock leather item and it only lasted 4 years - I hope the P5OC substitute lasts longer but doubt it as I suspect the bearings are going anyway

[johnbirmingham]

I was scheptical re. the relative merits of the seals too. The leather one had a corrugated spring steel band squeezing all the leather inwards as well as the conventional coiled spring ring acting on the lip.Neoprene obviously seals better when all is well so it may be that the leather one has the edge under partial failure conditions. John.