dave_h34 Posted April 16, 2019 Share Posted April 16, 2019 I'm part through disassembly to get my BMW diff out, in fact, the next step is the diff bolts themselves. Before I crack on as per all the guides I've read, is there a reason to remove diff and carrier from the car rather than remove diff from carrier? The latter would be slightly smaller to squeeze out and also would leave all the centralising shims in place. Or am I missing something? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted April 16, 2019 Member Share Posted April 16, 2019 Have you got John Vine's note about the correct placing of the Schnorr washers?Jonathan Link to comment Share on other sites More sharing options...
Area Representative Katie Posted April 16, 2019 Area Representative Share Posted April 16, 2019 HiI recently took my BMW diff out leaving the carrier in the car. This was fairly easy. I took the A frame off to give more room, which was also easy. The problem was to get the diff back in. Plan A was to leave the carrier in the car. However, this turned out to be very difficult. Plan B was to take the carrier out, fit the diff to the carrier and then fit carrier plus diff back in the car. This wasn't easy, but it was possible. I think the reason that Plan B worked better than Plan A is that there is no give between the diff and the carrier, but there is some give between the carrier and the chassis.Luckily a fellow member with much more skill and experience than me helped. Many thanks Graham.Hope that helps. Good luck.Ivan Link to comment Share on other sites More sharing options...
dave_h34 Posted April 16, 2019 Author Share Posted April 16, 2019 No I haven't, in fact, I don't even know what they are! Sounds like I should though... please. :-) Link to comment Share on other sites More sharing options...
dave_h34 Posted April 16, 2019 Author Share Posted April 16, 2019 Ah, OK, thanks for that. Makes sense. I must admit the wrestling back doesn't fill me with a warm fuzzy feeling. Link to comment Share on other sites More sharing options...
Area Representative Katie Posted April 16, 2019 Area Representative Share Posted April 16, 2019 HiJust one other thing.When you put the diff back in take care to keep both parts of the handbrake cable above the diff carrier. I didn't and I had to take the cable out after I'd got the diff back in and re-thread it through the right gaps.Ivan Link to comment Share on other sites More sharing options...
John Vine Posted April 16, 2019 Share Posted April 16, 2019 Re JK's post (#2) on Schnorr washers....The latest IKEA-style Assembly Guide has an error on page 95. It omits the two Schnorr washers for the lower diff bolts (green arrows):The previous (2015) AG said:"Attach the front end of the differential at the lower mounts; use the M12x55 capheads from the Z-Pack 30Z1067A (copper slip the shank). Take care to use M12 Schnorr washers underneath the head of the bolt."And this is a Schnorr washer: JV Link to comment Share on other sites More sharing options...
dave_h34 Posted April 16, 2019 Author Share Posted April 16, 2019 Thanks all, diff is out! Not nearly as heavy as I gave it credit for. So, next question, what's the preferred method of getting the back plate off? It seems gummed up pretty tight with sealant gunk. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 1, 2020 Share Posted June 1, 2020 Hi guys, Resurrecting this, I have just got everything ready to drop the diff but there looks no way it will come out between the de Dion, A frame and the chassis parts at the front. What Am I missing?Do you need to remove the A frame to allow it to swing a bit sideways? Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted June 1, 2020 Share Posted June 1, 2020 I removed the A-frame to take mine out, only takes a couple of minutes to take the 3 bolts out. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 1, 2020 Share Posted June 1, 2020 What about the ARB? That seems to be in the way too. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted June 1, 2020 Share Posted June 1, 2020 That, too. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 1, 2020 Share Posted June 1, 2020 Thanks, James. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 8, 2020 Share Posted June 8, 2020 Anyone know the torque settings for the diff to the diff bracket on the latest iteration of the bracket for the BMW diff? 2 M12 bolts forward and a bolt and nut top rear. My manual gives figures for an older bracket. Got my diff back from R and R today. Broken Bellevilles, broken carbon plates, bits in the pinion shaft bearing, a few miles away from a catastrophic failure, according to R and R. Complete rebuild needed.After only 8000 miles. Not impressed. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 8, 2020 Share Posted June 8, 2020 And does anyone know how much oil to put in? CC say 1.2L, RR 0.8L Link to comment Share on other sites More sharing options...
kiloromeo Posted June 8, 2020 Share Posted June 8, 2020 When I built mine with BMW diff (2018/19) the build manual stated 0.8L.As the general thinking was 'fill it til it runs out' , I actually put the supplied 1L in and it would have taken more (perhaps 1.2L ?). So I checked with Derek at Caterham and he said leave it at 1L. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 8, 2020 Share Posted June 8, 2020 Thanks k. I’ve always filled to the hole which has been about 1.2L. I’ll go with 0.8 on the basis of what you said. As far as I know the reason for the lower amount is because 1.2 will cause leaks through the side seals, though I never experienced that Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted June 9, 2020 Area Representative Share Posted June 9, 2020 Some output seals leak some do not. I found that the original output seals on my diff were not set far enough into the casing allowing the rotational variation of the shafts to impinge more on the seal lip. They leaked after 3 years & 10000 miles.Opinions vary on the oil level because of the differences in build manuals but the current advice of 0.8L is about right to negate any leaks from the output seals. I must admit the level of my diff has always been 'until it runs out' even after the seal change with no problems. That statement of course is a harbinger of doom!QUESTION: when did CC implement the fitment of carbon plates? Link to comment Share on other sites More sharing options...
ScottR400D Posted June 9, 2020 Share Posted June 9, 2020 Thanks Geoff. Yes, the question of when carbon plates were fitted from still remains. My car was supplied as a kit in December 14, and it had carbon plates. Talking to Phil at RR he said that the carbon plates worked well for a long time then something changed, maybe an adhesive or something else in the process, when they began to fail after a short time and were replaced by the sintered plates. To be honest, it’s a concern to me. If the diff can get into the state mine was in in 8000 miles, and it wasn’t just the plates that had failed, how are they supposed to be fit for purpose? Link to comment Share on other sites More sharing options...
ScottR400D Posted June 12, 2020 Share Posted June 12, 2020 Well that’s all very disappointing. All back together with completely rebuilt diff and the tapping noise on overrun is still there. No noise even with the slightest bit of throttle, just on overrun. You can hear it with car jacked up and spinning wheels, as soon as you stop, tap, tap, tap.......... Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted June 12, 2020 Share Posted June 12, 2020 That's annoying.Slip-stick under preload of the replacement sintered steel plates, perhaps? Supposedly one advantage of the carbon plates over the sintered steel ones is lower operating noise.Is it running 75w140 oil? I found that weight quietened down my diff somewhat, although mainly reducing whine. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 12, 2020 Share Posted June 12, 2020 No, James, I don't think its that. I made a recording of the tap and sent it to Phil at Road and Race. He seems certain it's not the diff, thinks it more likely to be one of the compensation springs/plungers in the drive shafts.To be fair, he's probably right. Before I stripped all out it was making this noise as well as others from the diff. The diff has had just about all new parts but for the CW and P and the frequency of this noise (2/ wheel rev) doesn't fit with them. He also says that they showed no damage.So, got a pal coming round to pinpoint the location of the noise while I rotate the wheels then I'll do one shaft at a time, and strip them right down. They seemed fine on the bench before but maybe not.Anyone got a supplier of the springs/plungers, boot clips etc?PS The diff is quieter than it was, the chattering on overrun has gone and the car also behaves itself better coming out of corners accelerating away in lower gears. The fishtailing has stopped now it just seems to be a nice progressive drift, if the tyres lose traction. Link to comment Share on other sites More sharing options...
Tazio Posted June 12, 2020 Share Posted June 12, 2020 Redline and CC do a boot and clip replacements for the tripoid joints, including pouches of the very specific grease thats for tripoids, haven't found a source of the springs or plungers, which I presume are GKN bits.The irony is I have a sierra diff with Titan lsd, just been fully rebuilt, along with new UJs in the propshaft, and I too have a tic tic tic....that wasn't there before...I thought it was the outer CV on the nearside driveshaft, I dismantled it, cleaned it, regreased it, found nothing, replaced and tic tic tic...annoying isn't it ! Link to comment Share on other sites More sharing options...
ScottR400D Posted June 12, 2020 Share Posted June 12, 2020 Oh yes, it's annoying! I wouldn't mind a tic tic! Mine is a deeper tapping sound. After the car had run, I jacked it and span the wheels; the tapping was quite clear. Now that it's cooled, it's much less noticeable but it's still there. I'm wondering if this points to a driveshaft, the sound being clearer when it's hot and the grease thins a bit but masked by the grease when cold. Then again, if it's this fabled spring, it's probably not much lubricated by the grease anyway!The wonders of 60s' engineering!!If I knew how I'd upload the sound file! Link to comment Share on other sites More sharing options...
Tazio Posted June 12, 2020 Share Posted June 12, 2020 Exactly the same symptoms, louder after a 20 mile run when things are warmer, my spring and plunger cap are ok, on the end of the driveshaft i thought it was, I was also thinking of removing the caliper, and spinning the wheel, just to make sure it's not caliper/pad related. Link to comment Share on other sites More sharing options...
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