My differential is leaking so when it started raining I started tearing it apart. I thought by the parts book I would be able to remove the bolt in the center of the flange and slide it off and get to the seal. This bolt has not yet simply unscrewed. Before I go further I thought I'd ask the few out there who have been here, how exactly do I get to the seal? Image Unavailable, Please Login
Don't quite understand this description. Hold the flange stationary and remove the bolt and the large flat washer -- then the flange can be slid off of the splined shaft showing the seal (which rides on the OD of the flange). See page D19 in the 308GT4 WSM for a cross-section drawing.
Brian: Make sure you use OEM seals here. I used seals from superformance in the UK and they are unfortunately not quite right and leaked on the right side. Problem solved with correct seal. Stacy
Brian, What ever you do, PLEASE post pictures of what you do. Some of us will have to or need to do this project soon.... JIM
oh gawd I went thru this about 2yrs ago, what a mess. did it more than once, actually it took me 3 tries to get it right inside of one week. I think there is a post of it most likely in the archives. the seal helps but the final fixer was using anaerobic sealant on the threads. and then using the porsche flange plate that keeps the cv grease in the cv. I did both sides, not wanting to go thru it again. wish I had done when I had the motor out just 1 month prior - doh!
By "simply" I mean I put a wrench on it and couldn't loosen it, I used an air impact on it (with a long power-sapping extension) for a bit and it didn't budge. Before I used more persuasion I thought I 'd make sure I was doing the right thing. I will get a better grip on the flange somehow and go at it again. Thanks!
Which threads are you refering to? I know I have much leakage from the seals. They started leaking as soon as I changed the tranny fluid to synthetic Redline. (I even made some "heat shields" to keep the oil from flinging all over the place, mostly onto the headers where they make scary smoke as seen through the rear-view mirror. You can see a little bit of the shield in the picture.) What I wan't expecting is that the inner CV grease was very thin, probably diluted with tranny oil. So it must be leaking past that bolt (that I haven't removed yet). So I will seal that bolt as well, I suppose. Is that the threads that you are referring to? And don't woory, Jim, I'll post pictures of my adventure. I'm doing stainless braided brake lines, new suspension bushings, the diff output seals, new CV grease and probably new axle boots.
the bolt holds a large washer that you see, the output shaft stub is hollow so the bolt has to seal the diff/trans oil. there is a 'O' ring that fits to the bolt much like the cam bolt, actually the setup is similar to cam bolt. i used a long round prybar to hold the flange against the housing and then break the bolt loose. redline has very good hightemp cv grease.
The factory calls for applying silicone sealant on the splines before reinstalling the drive flange and applying some to the shank of the bolt. When it is all reinstalled that will prevent oil seepage into the CV joint. If the CV joint has not had too much grease put in it (Yes there is a maximum amount) and of the correct type, it will not migrate out of the boot flange/drive flange joint even when installed without sealant. That is the way Ferrari did it and it works very well.
I am installing superperformace seals this week, will add some pix as well... I hope they fit, I see no reason they should leak. They are made by MKS. ( http://www.mksinst.com/ ) Are the "center bolts" std thread or any of the sides "links"? rgds Trond
I tried the silicone sealant and it still leaked, upon dis assembly I found the silicone to not have setup, so I went to an anaerobic sealant. worked great after that. what silicone are you using?
I have used almost every brand in that application with no trouble. Surfaces need to be clean and dry. Never ever had a problem on those. Some other places sure.
I use Permatex Ultra Black sealant. (The Ultra Blue also works well, but is highly visible if a thumbprint gets on the wrong place. ) The Ultra Black has always worked to seal the differential splines for me. Again, I've always thoroughly cleaned the splines & flange before reassembly. However, the ultra black is somewhat oil tolerant, I have had it seal surfaces that I couldn't thoroughly clean for whatever reason.
Well, I'll finally be trying one of those sealants because I finally got that bolt out. I haven't yanked the seal out yet. Can I remove the whole "carrier" that the seal is in? Or is it clamped in place by the diff case? I thought it just might be easier to do the seal on the bench. Image Unavailable, Please Login Image Unavailable, Please Login
A big ol' breaker bar and a few long entensions to clear the wheel well. I ran a couple of bolts through the holes with nuts on the back side to stop the flange. I applied heat with a propane torch, let it cool a bit and then carefully tunred it. So can I pull those nuts and remove that plate that the seal is in? Or does that stay put? I'm probably going to try it if no one stops me.
If the lateral cover -to- diff case cover isn't leaking, I wouldn't pull the lateral cover off just to replace the seal as you just risk messing up the bearings and preload for very little gain IMO (you can note that on the other side you don't have that "choice" for getting the seal out). One could argue that it actually adds work because you'd need to clean things up and reseal (and then hope the preload is still OK). JMO.
I went to the garage last night and contemplated pulling the whole carrier, but thought I'd give it a shot in palce first. The seal popped right out. Super easy to pry it out with a screwdriver. It actually came out so easily that the seal looks reuseable, unlike most seals that would be warped and dinged - not that it will get reused. The outside perimiter of the seal was coated in clean oil. I think that the seal was leaking between the seal and the case and maybe not, or minimally, from between the seal and the shaft. This is the old seal and the new seal's box. Image Unavailable, Please Login
I cleaned the bore and the splines with paint thinner to remove the oil from the mating surfaces. I used a toothbrush on the splines, both on the diff and on the flange. I cleaned up the seal surface on the flange with Scotchbrite. The seal surface doesn't look perfect. Hopefully the new seal will ride on a slightly different spot. If not this will require a revisit in the future. But it has got to be better than what I had, which was major leakage. Image Unavailable, Please Login
I put the lightest smear of anaerobic sealant on the outside of the seal and pressed it by hand. I used a 1-7/8" Craftsman socket that happens to match perfectly the outside diameter of the seal to persuade it all the way home with light hammer taps. You probably have a 1-7/8 socket, right? It fits the front crank bolt on Triumph Spitfires. Image Unavailable, Please Login Image Unavailable, Please Login
I put a small amount of RTV on the splines and used a squirt of blue RTV on the back of the big washer, lined up the punch mark on the washer with the hole in the flange and screwed the bolt in. Normally I put the lightest coating of RTV possible on what ever I use it on, but there isn't really any good way for the excess to get in the tranny, the excess came out from under the washer. And for the RTV Police and newbees, even then it isn't that much RTV, maybe two toothpaste servings, one of which came out from under the washer and got wiped away. So the seal is in, and time will tell if it works. Before I put everything back together I have a bit of refurbishing to do, painting A-arms, replacing bushings, new boots, etc. Before putting all the stuff back in the car I'd like to move it out of the garage and hit this area with a round of engine cleaner. I haven't quite figured out how to move a three-wheeled car. Furniture dolly under one corner, maybe? Image Unavailable, Please Login Image Unavailable, Please Login
I also removed the first a-arm bushings last night. Good, stinky fun! Image Unavailable, Please Login
How did these seals work out? Did they leak? My flanges are in similar shape to the ones in the post. Are these the OEM seals:? http://www.woodys-auto-supply.com/auto-part-details.asp?prod=SKF-564129 Or is there an upgrade?
The car is back together and I drove it around the block a couple of times and then went Vegas for a week. I go home tomorrow (yay!). Hopefully I can put a few miles on it this next week. And I hope all the oil stays in!! I did not use seals from a Ferrari supplier. I almost wrote OEM seals, but who made/makes the OEM seals? Might even be SKF for all I know. But in any case SKF seals are supposed to very good. And with the slight pitting on one flange, any leakage on the driver's side might not be the seal's fault. But I didn't think it would be a problem. Oh, and the hilarious part is that I bought seals locally in advance (as well as brake lines and a-arm bushings) of this project so that I could have it done as quickly as possible. Now I look back and it took two months!
