M_Ratcliffe Posted January 17, 2021 Share Posted January 17, 2021 Hello, first forum post here. Im hoping that someone with a bit more experience than myself would share their input on interpenetrating the gear mesh imprint images attached. History/Background: Series 3 109 197X running a standard issue rear Salisbury axel and 4.7 diff. When replacing the pinion seal on the rear diff, I noticed quite a lot of play in the pinion and no preload. So off came the pinion seal and preload washers [ in this case a crush sleeve] here is what came out:- Oil frow washer [607182] deformed.- Crush able collar [ 607197 measures 27.2mm] lipped as if it may have been loose on the shaft.-No gasket seal [607183] to be seen I believe what occurred here is the crush washer was over crushed and everything on the pinion side that is usually held in place via friction was free to rotate. So off came the rear diff cover for a quick inspection: -Sun gears have quite a lot of play, going to try and see if new gear shims [607169 & 607168] fix this, or if new gears are needed. -Gear mesh imprints look out of spec, but as this is my first time doing them I would really appreciate your view on them.. -Pinion crown backlash is 0.4mm [I believe the new spec is 0.2mm] As said earlier this is my first time inspecting a differential, How bad are my gear mesh imprints and what do I change to make them correct? My theory is that the pinion shim will look like the oil frow washer and have become worn/lipped due to no pinion preload, Would the gear imprints indicate the need to increase the shim on the pinion gear? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 18, 2021 Share Posted January 18, 2021 The main problem I think you are going to have is that with zero preload and thinks loose the CW and the Pinion will have been meshing poorly / incorrectly and as such will have worn incorrectly. If so no amount of re jiggling is going to return it to good, and as such the prints will be poor. Its really more as to how fussy you want to be - salisburys are an ancient diff a la DANA 60 which are clunky anyway even when rebuilt properly, and rarely fail, they will end up making more noise than your ears can take pre failure, so my advice is to do the best you can and then see how noisey or not is it, as I am guessing you won't get a proper pattern now due to damage Nige 1 Quote Link to comment Share on other sites More sharing options...
M_Ratcliffe Posted January 18, 2021 Author Share Posted January 18, 2021 Hi Nige, thanks for the reply. In your opinion do the gear imprints indicate that its worn unevenly? I dont know the full history of the land rover, it came to me as one of those "almost finished projects, needs trailer to collect" with a few owners in between being taken off the road and being put back on. Im not sure just how long the pinion has been like that, it could have only been the 50 miles I put on her prior to a more in depth spanner check.... Most of the other parts of the car that required shimming/spacing, contained all the shims provided/found in a rebuild kit. Getting them some what like was just as simple as removing the unnecessary ones. Im willing to open the wallet for things when needed, but happy to work on a budget if it gets it somewhat near the original tolerances. Surprisingly the rear diff wasn't noisy, even with no preload, the front one was. Mike Quote Link to comment Share on other sites More sharing options...
mickeyw Posted January 19, 2021 Share Posted January 19, 2021 NIge I was looking at those mesh imprints and thinking how unworn the teeth appear in general. I think the contact point is not perfectly positioned, but it's far from terrible either. It looks a little more inboard than I would expect. However you have far more experience than I do in this area. To the OP - Welcome to the forum. Great to see a well written post with some clear photos How much in-out play would you say there was on the pinion - was it particularly noticeable? Since you have dismantled things this far have you removed the pinion bearings to check their condition? Did you find any debris in the bottom of the casing? The whole diff looks pretty clean compared to many we see. Quote Link to comment Share on other sites More sharing options...
M_Ratcliffe Posted January 19, 2021 Author Share Posted January 19, 2021 (edited) Hi Mickeyw, thank you for the input and the questions it does get the brain thinking. I didnt measure the in-out play directly, because it felt too loose up/down to give any real information once the seal was removed. I did however fit a 2.5mm shim in between the crush sleeve and bearings, torqued her up snug but not enough to deform the crush sleeve and compared how much the pinon flange moved out compared with just snug and no spacer. The 2.5mm spacer moved the pinion flange out by a further 1.65mm, by my maths this means the crush washer had worn down/deformed by 0.85mm past its useful service [ball park numbers]. That isnt to say the flange nut was tight and this gap could have been larger whilst in use. Crown wheel was well situated, no side to side movement when lightly pried/pushed, runout was close to zero, backlash was around double what the recommended setup backlash is. Its all out on the bench now: All bearings look to be in ok condition [ pinion and diff assembly ones], mating surfaces smooth and just visible witness marks in all the races that would indicate they have operated well centred for the majority of their life. Spider gears had a lot of play/backlash but I believe this is a common problem on the Salisbury, the Cross shaft appears to be in good condition with no grooves, all the gears have teeth and no grooves. Just waiting for replacement shims to compare their thickness to new. Looking in the now bare axel case, there are signs that this has had a diff replacement, a few small 1mm2 remnants of gear teeth in nooks and crannies [ all the gears in there now are full]. In the axle case between the pinion bearings, what looks like short lengths of what was once brass brazing rods, I dont believe there are any brass pieces in the Salisbury axle so pretty sure someone left them in the case by mistake or attempted to bodge a crush able washer extension ring. The current plan is to: Shim the play out of the sun/spider gears Clean the axle case and refit new bearings all round Shim the pinion and carrier to get the gear witness marks more centred in regard to toe and heel Refit a crush sleeve to spec with new splash washers etc, remove it and make a solid shim the same length on the lathe Double check prop shaft lengths Fit some magnetic sump plugs from Nige The shimming of the pinion and carrier might be a bit optimistic for a first timer, there is a random old rover diff on the bench that im using for practice as its easier to shim and not expensive if I make any large mistakes. "I think the contact point is not perfectly positioned, but it's far from terrible either. It looks a little more inboard than I would expect. " << Still learning the nomenclature, in simple terms do you mean the drive and coast are not centred heel to toe and the pinion needs further shimming? Any input is really appreciated as it gives me somewhere to start. Mike Edited January 19, 2021 by M_Ratcliffe Quote Link to comment Share on other sites More sharing options...
M_Ratcliffe Posted January 20, 2021 Author Share Posted January 20, 2021 Update for anyone watching/interested in what the effects of no pinion preload can be. A bearing puller arrived today in the post and allowed the inspection of the pinion bearing face. The pinion and bearing centre have been spinning and lapped/ground into each other on the bearing side it equates to around 0.08-0.1mm. 2 Quote Link to comment Share on other sites More sharing options...
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