I’m looking for technical help or recommendations on: __
Im thinking specifically about changing from an open to a limited mechanism without the whole housing change which is probably how this is usually done.
Whether open or limited the actual mechanism is just bolted on to the rack and pinion mech. The pinion is the same across models so the temptation is to just change the rack. Not good practise engineering wise but doable if your engineer blue says it’s ok😀
Anyone been here/done it?
I’m looking at a cheap LSD with the wrong gearing for my 5 speed as a winter project.
Thanks
Well thanks for your opinions😀 I’ve pulled the trigger on an LSD for £155 posted so hopefully this will be an interesting winter project with not too much downside if it doesn’t work out….
Got to be surprised at so little response to this post. Are 1.8 owners all old ladies?
I’m not entirely sure about the advantages of LSD but I’m deffo irritated by the lack of it. So often you pull out quickly and there is all this unnecessary wheel spin. That’s just one example, but it’s my thinking it should be standard on a rear wheel drive car. Without it the vehicle is incompetent in certain circumstance. Not acceptable in a car with pretensions to pleasure driving?
Whatever, it looks that I can just keep all the dimensions and clearances of my current diff and just swap the open mech to a limited slip one.
Be handy if someone could point out problems before I come across them myself.
The centre part of the diff which includes the ring and the LSD element can only be removed after pulling the driveshafts… Which needs hubs etc to be pulled. Swapping the ring of your old diff to the ‘new’ LSD can then be done but ‘backlash’ between ring and pinion needs to be set. Achievable in situ for sure but you need good access under the car to achieve.
To drop the diff also needs the PPF (powerplant frame) to be disconnected… More exhaust parts dropped etc…
So I’d love to hear how you get on !
In a few weeks I’m doing the ‘inverse’… Have to move my old LSD into a ‘new’ housing / ring / pinion.
While you have things apart also change out side bearings and seals in the diff.
The ring and pinion are matched to each other… You can’t use a 4.1 pinion (which is what your 5spd should have… Might be 3.9) with a 3.7 ring (which is what is used with most LSD units, fitted to 2.0’s)… So you’ll have to move the ring from your old diff to the LSD element from the new diff.
Thanks for the insights. First thing will be to strip/ rebuilt the bought-in diff to get a feel for it.
I’m hoping to keep my own diff( and it’s settings) and just swap out the open mech for the LSD of the bought in one.
I doubt it will be that simple but I’m keen to see if it can be done with the casing in situ. I’ve a dial gauge and some engineers blue somewhere in the house that needs tracking down.
Whatever way it’s goes the LSD bought in should be easy enough to move on given the purchase price.
Good luck with your project👍
Oil seals are in the diff housing, ie the bit you are going to keep off your car, seals are cheap enough so might as well fit new ones when you have the insides out.
Bearing are on the LSD part, ie the bit you have bought in. I’d suggest you swap the bearings out. So, strip the LSD diff, remove the ring (might need a heat gun on it to ‘expand’ it so you can get it off the LSD centre)… Then puller time and pull the old bearings off and fit new ones… You can do all that before you pull your diff out of the car.
On swap day (or swap week end lol)… Pull the centre open section out of your car… Pull the ring gear off and fit it to your ‘prepared’ LSD, swap the oil seals out as suggested above and then start the re-installation.
Pinion depth is probably ok and you’ll get away with putting back in whatever spacers came out of your diff… Obviously check… But engineers blue can dry really fast and is often used for marking out… The diff contact area grease is usually yellow… So just check what you have is suitable before you NEED it… Maybe practice on the ring and pinion in the diff in the shop before you take it apart.
Obviously, use the right gasket sealant when you are putting the casing back together… And make sure you use GL5 oil when you refill the diff… It has additives specifically for diffs.
As soon as you remove the differential from the case you’ll lose its 'settings '… swapping the centre means you’re definitely going to have to set the backlash…
Thanks again. Your comment about engineers blue is welcome. I mentioned it just to say I’ve been around engines where it’s not just screwing stuff together. So point taken.
Anything disturbed is not going to return perfectly but I worked for years on camshaft drives with this system. As long as the shimming was not altered they went back without problem after being removed from the cylinder head for gas flowing.
It should be easy enough to take pics of the diff tooth pattern before changes and use that as a guide.
The pinion, with the much smaller number of teeth is the one not to mess with. It can only be altered by shimming and that shimming would have been setup at the factory.
Key thing here is to use the bought in diff to get a feel for the mech. I’ve a nice work bench so hoping to screw the diff down to that in a custom way rather than rolling around on the floor with it…
You’re right, the pinion will remain in your diff in the car and pinion depth will remain unchanged… The only thing you’ll have to adjust is backlash when you fit the LSD element with your old ring gear back into the diff housing in your car. That’s the bit you need to practice on the bench so you are comfortable doing it upside down under your car.
Well it arrived today. How you pack something that is hard to lift is a bit of a problem. The guy had wrapped it in a lot of wool and bubble wrap in a sturdy cardboard box but it’s a miracle it survived . I think it was mostly down to it was too heavy to throw!
Anyways it’s on the bench and just needs to be secured so I can work on it. It’s gross and heavy from the outside but once you get inside it will be all about finesse…
