jjsanz Posted July 4, 2012 Share Posted July 4, 2012 Hi, has anyone attempted to change the drive pinion oil seal on a Sierra diff, with the diff in-situ! Is there enough space to swing a spanner or get a two legged puller in there! Just thought I'd check before stripping the rear suspension! Link to comment Share on other sites More sharing options...
charlie_pank Posted July 4, 2012 Share Posted July 4, 2012 Stripping the rear suspension is really not that big a deal. Maybe you could do the seal replacement with the diff in situ, maybe you couldn't but I'll bet it's easier to take the diff out first. You're going to have to get the oil out of it anyway aren't you? When you replace the seal, do you need to re-align the pinion bearings? If so there's no way you're going to do that in-situ! Link to comment Share on other sites More sharing options...
mav Posted July 4, 2012 Share Posted July 4, 2012 I believe it can be done in situ as you don't / shouldn't need to realign the bearings... As it happens I've been thinking of doing this. I know for a fact that when one was replaced under warranty on my car, the ford agent that did the work did NOT remove the diff from the car. Link to comment Share on other sites More sharing options...
jjsanz Posted July 4, 2012 Author Share Posted July 4, 2012 Looking at the Ford manuals for the diff and seal replacement, the flange nut just holds the flange to the drive pinion. There's a separate nut revealed when you remove the flange, that holds the drive shaft and bearings in place, so I'm confident that there's no need to reset the diff. The Ford Scorpio manual shows the seal being removed with diff in car and makes no mention of resetting anything! Of course, you've got better access under the Scorpio. Probably easier (and quicker) to remove the diff from the car, I can then drain off oil, remove backplate and inspect the condition. Just wondered if anyone had tried to do this on the car. Link to comment Share on other sites More sharing options...
The Pikey Posted July 4, 2012 Share Posted July 4, 2012 I would defo take the diff out but I doubt it's going to possible to do it in situ anyway because of the prop being it the way. As far as getting the flange off, other than the 4 threaded prop bolt holes there are another two plain holes, these are to locate the tool in which stops the flange turning when you try undoing the nut. The nut holds nothing on apart from the flange. The old seal can be a right bugger to get out too and obviously it's important to get the new one in straight as well. Once the car is up on the stands I can get a diff on the floor in 30 mins so thats the way I would do the job. The time spent taking the diff out will be time saved plus a bit on getting flange off and the seal in and out. Jason Link to comment Share on other sites More sharing options...
mav Posted July 4, 2012 Share Posted July 4, 2012 I may have been confused, so to clarify I was talking about the drive shaft oil seals, not the drive flange at the nose of the diff. Sorry. Link to comment Share on other sites More sharing options...
The Pikey Posted July 4, 2012 Share Posted July 4, 2012 BTW, to get the diff out you don't need to take the Dedion tube out and if the car is high enough the A frame can swing forward when the rear bolt is removed and the forward bolts & spacing washers are just loosened. J Link to comment Share on other sites More sharing options...
simonpa Posted July 4, 2012 Share Posted July 4, 2012 As Jason says - you can drop the diff by just loosening the front A-frame bolts, undoing the rear A-frame to dedion bolt and swinging it down. It may just be possible (if the car is high enough) to just undo the prop bolts and the lower 2 diff bolts and then swing the diff back and up to reveal the nose/pinion enough to work on it. You may be able to do this without removing the driveshafts.. If you need to remove the diff, you don't need to undo much on the back: o undo the 2 bolts on each caliper and pull it up/tie to the rear springs o undo the 4 bolts holding the bearing carrier to the ears o pull the hub/driveshaft assy out through the ears (no need to undo the big nut) o undo the 4 prop bolts o undo the 2 lower diff bolt and take the nut off the big upper diff bolt o support the diff on a trolley jack (get someone to hold it steady o drive the big bolt out o lower the diff down and slide it out Simples? HTH - Simon Link to comment Share on other sites More sharing options...
jjsanz Posted July 4, 2012 Author Share Posted July 4, 2012 Thanks for the tips and tricks. I think I'll remove the diff and then attack the seal on the bench. Link to comment Share on other sites More sharing options...
charlie_pank Posted July 4, 2012 Share Posted July 4, 2012 I've had the diff in and out of the car quite a few times recently and until the last time have always done it with the dd tube in place. Last time I took the dd tube out to do it. It's so much easier, I'll never do it with the tube in place again! Link to comment Share on other sites More sharing options...
Englishmaninwales Posted July 5, 2012 Share Posted July 5, 2012 Replacing the nose seal doesn't always stop an oil leak from the nose of the Sierra diff(presuming thats why you're changing the seal). Phil at R+R advised me as follows: When the flange is off, chemically clean the splines and the flange with brake cleaner and reinstall the flange on the splines with a liberal amount of RTV. Cured my oil leak that persisted after changing just the seal. Undoing the flange nut is best done with the diff out, undone with an air gun at a garage or ATS. Link to comment Share on other sites More sharing options...
Mankee Posted July 6, 2012 Share Posted July 6, 2012 Quoting simonpa: As Jason says - you can drop the diff by just loosening the front A-frame bolts, undoing the rear A-frame to dedion bolt and swinging it down. It may just be possible (if the car is high enough) to just undo the prop bolts and the lower 2 diff bolts and then swing the diff back and up to reveal the nose/pinion enough to work on it. You may be able to do this without removing the driveshafts.. If you need to remove the diff, you don't need to undo much on the back: o undo the 2 bolts on each caliper and pull it up/tie to the rear springs o undo the 4 bolts holding the bearing carrier to the ears o pull the hub/driveshaft assy out through the ears (no need to undo the big nut) o undo the 4 prop bolts o undo the 2 lower diff bolt and take the nut off the big upper diff bolt o support the diff on a trolley jack (get someone to hold it steady o drive the big bolt out o lower the diff down and slide it out Simples? HTH - Simon Ruddy good guide there, Simon! I was about to grind down my 41mm socket so that I can fit it through the wheel centres to undo the driveshaft nuts. Seems like I won't have to now. Link to comment Share on other sites More sharing options...
weeman Posted July 6, 2012 Share Posted July 6, 2012 I would add to Simons guide that, I also remove the boot floor. This takes five minutes but allows easier access and enables one to cradle the diff in a rope sling wrapped around the rollover bar. Done this job more times than I care to remember on both De dion and an IRS 7's Be lucky!! Martin Link to comment Share on other sites More sharing options...
DaveMorris Posted July 6, 2012 Share Posted July 6, 2012 One thing I've not seen mentioned above (though it is late and I have had a couple of beers) - there are washers on either side of the diff, to centralise it. Before removing the diff, either measure the gap at either side of the diff to the mounting points, OR when removing bolt(s) make sure that you catch the washers from each side. There may be different numbers each side, and colecting them means that you don't have to go to all the faff of installing diff, measuring, removing, changing washers around, re-installing etc Dave Link to comment Share on other sites More sharing options...
jjsanz Posted July 15, 2012 Author Share Posted July 15, 2012 Thanks for all the info. I've started to take the rear apart and had just a couple more questions if I may. 1. Noticed that one end of the A-frame bushes had two large washers between it and the chassis, is this common!! 2. There are two large metal P clips attached to the top of the diff, holding the handbrake cable in place, are these just riveted on to the diff? Can they be drilled out and replaced? Or do you guys just tie-wrap the brake cable to the diff! 3. What thread lock do you use on the bolts holding prop-shaft to the diff? When I took the prop-shaft off the flange, I got a trickle of oil come out, so I guess my leak is between the input shaft and the flange and not the oil seal as there is no oil between the flange and the diff housing!! Link to comment Share on other sites More sharing options...
The Pikey Posted July 15, 2012 Share Posted July 15, 2012 Quoting jjsanz: Thanks for all the info. I've started to take the rear apart and had just a couple more questions if I may. 1. Noticed that one end of the A-frame bushes had two large washers between it and the chassis, is this common!! 2. There are two large metal P clips attached to the top of the diff, holding the handbrake cable in place, are these just riveted on to the diff? Can they be drilled out and replaced? Or do you guys just tie-wrap the brake cable to the diff! 3. What thread lock do you use on the bolts holding prop-shaft to the diff? When I took the prop-shaft off the flange, I got a trickle of oil come out, so I guess my leak is between the input shaft and the flange and not the oil seal as there is no oil between the flange and the diff housing!! 1. Yes, it will have been measured to centre the DD tube. They need to go back as they were. 2. I'd drill them out and use tie wraps when it goes back in. 3. I just used the medium strength blue stuff Looks like you have oil travelling up the splines, when the flange goes back on I would ensure all the oil is off the splines and slide it on with RTV. Jason Link to comment Share on other sites More sharing options...
jjsanz Posted August 2, 2012 Author Share Posted August 2, 2012 Used some black RTV, as used to make gaskets for oily bits and put everything back. Getting the washers back in place was quite challenging and took most of the time, anyone thought of machining a solid washer to the correct width, would save a lot of effort! Anyway, all back together, working and so far no leeks, fingers crossed. Thanks for all the advice. Link to comment Share on other sites More sharing options...
DaveMorris Posted August 3, 2012 Share Posted August 3, 2012 Re the washers - many people get spacers machined which are the correct width for THEIR CAR to save the faff with multiple washers. The reason for multiple washers in the first place is to ensure correct centering of the diff - and each chassis can be very slightly different. Dave Link to comment Share on other sites More sharing options...
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