switching an LSD between transmissions

[kinkyllama]

Anyone wanna walk me through it? It's my understanding that if the LSD is already installed in one transmission all I have to do is swap over the differentials.

Thanks!

[PrecisionBoost]

Ya..... it shouldn't be too hard..... I have the factory service procedures for removing the differencial if you need them.

The biggest problem is that there is a special tool required to disassemble the tranny..... basicly it's a GM tool that has to bought from a dealer.

I think it's rather expensive if I remember correctly.... I was planning on simply making one.

When I get home I will try and dig up some info for you.

As well.... you could search migweb, astramk2 and other forums like that since there will be "how to" posts or sections on the transmission disassembly.

Most of them had the F16 and F20 which is virtually identical to your D20 forenza transmission.

I also am having troubles with the 2nd gear syncros when the tranny is cold..... one of these days I'm going to have to look at putting in a different tranny fluid before they go away for ever.

Most of the time I simply double clutch....which isn't hard if you get use to it.

Many race/rally car drivers have to double clutch since they are using dog boxes (straight cut gears with no syncros )

Once you get really good at it you can also throw in Rev matching..... basicly when the RPM of the engine match the RPM of the tranny gear your selecting you can shift without a clutch.

Quaife makes a dog gear upgrade for the F20/F16.... they will increase power handling capacity big time.... but double clutching is something that has to be done all the time.

On this next tranny.... perhaps you should consider learning to double clutch to avoid smoking your syncros..... it can be done just as quick as a regular shift if you practice.

But when practicing you have to be carefull not to grind the gears.... I'd suggest trying it first on a straight line so that you don't have to deal with multiple things at once.

[PrecisionBoost]

Oh.... for the record.... I had to double clutch my 83 Celica GTS for nearly a year because the syncros were screwed.

You would be surprized at how weird it feels to back to regular shifting once you've spent that much time double clutching and RPM matching.

RPM matching with shifting regularly is also a really good idea... then the syncros do not have to work as hard to match the speed of the gears.

[kinkyllama]

Ya..... it shouldn't be too hard..... I have the factory service procedures for removing the differencial if you need them.

The biggest problem is that there is a special tool required to disassemble the tranny..... basicly it's a GM tool that has to bought from a dealer.

I think it's rather expensive if I remember correctly.... I was planning on simply making one.

When I get home I will try and dig up some info for you.

As well.... you could search migweb, astramk2 and other forums like that since there will be "how to" posts or sections on the transmission disassembly.

Most of them had the F16 and F20 which is virtually identical to your D20 forenza transmission.

I also am having troubles with the 2nd gear syncros when the tranny is cold..... one of these days I'm going to have to look at putting in a different tranny fluid before they go away for ever.

Most of the time I simply double clutch....which isn't hard if you get use to it.

Many race/rally car drivers have to double clutch since they are using dog boxes (straight cut gears with no syncros )

Once you get really good at it you can also throw in Rev matching..... basicly when the RPM of the engine match the RPM of the tranny gear your selecting you can shift without a clutch.

Quaife makes a dog gear upgrade for the F20/F16.... they will increase power handling capacity big time.... but double clutching is something that has to be done all the time.

On this next tranny.... perhaps you should consider learning to double clutch to avoid smoking your syncros..... it can be done just as quick as a regular shift if you practice.

But when practicing you have to be carefull not to grind the gears.... I'd suggest trying it first on a straight line so that you don't have to deal with multiple things at once.

I have a service manual as well, I'll have to dig it up. Tom burned it onto a CD for me sometime ago and I keep forgetting how helpful it is.

Blah...I've tried double clutching and actually did it for awhile and just dont like it at all. I hate to be staborn but I rather go through sychros than double clutch.

I can rev match very well though and when I'm feeling lazy or tired I dont even use the clutch, just rev match. Never tried doing it racing though, its something I would have to get really really really good at on the race track taking it easy as if you screw it up going into a corner and jerk the car it could cost me big time.

I think where I actually really screwed up the sychros is shifting too fast, I never knew untill 6 months ago that it was bad. Now I can't shift fast at all or it grinds horribly. Also me, my gf, and my mom learned stick on my car.

[MMamdouh]

Oh.... for the record.... I had to double clutch my 83 Celica GTS for nearly a year because the syncros were screwed.

You would be surprized at how weird it feels to back to regular shifting once you've spent that much time double clutching and RPM matching.

RPM matching with shifting regularly is also a really good idea... then the syncros do not have to work as hard to match the speed of the gears.

so if someone is often downshifting from 3rd to 2nd without RPM matching then this would screw his 2nd gear syncro... right?

if i am right then i now know why my 2nd gear "bites" a little now

MMamdouh

[kinkyllama]

so if someone is often downshifting from 3rd to 2nd without RPM matching then this would screw his 2nd gear syncro... right?

if i am right then i now know why my 2nd gear "bites" a little now

MMamdouh

I think its pretty harsh on everything to downshift without rev matching. Either way practice rev matching, once you get good at it it'll be so much fun you'll do it every time you slow down.

[PrecisionBoost]

Also me, my gf, and my mom learned stick on my car.

Ahhh.... now the real reason for killing the tranny comes to light

Double clutching can be done super quick if the pedal travel is minimized via an adjustable bracket.

Basicly the bracket limits the movement of the pedal such that it barely disengages the clutch...... then you don't have to move the pedal eight inches just to make one shift.

I read a build up on this modification several years back..... basicly they adjust the unit by putting all four wheels up on a hoist.

Then they put the clutch in, put it in gear and slowly let out the clutch until the wheel starts to move ever so slightly (indicating the point where the clutch is touching the flywheel)

They mark this, install the bracket and then test it.

They push the pedal down until it bottoms out on the bracket and ensure that the wheel doesn't spin..... then they adjust the screw to move the bracket up (while clutch is fully depressed ) until the wheel starts to spin slightly..... then they back the screw off two or three turns.

I belive they also adjusted the rebound... since in most cases the pressure is taken off the master cylinder well before the pedal comes back to the normal rest position.

They did say that the clutch bracket should be tested on a regular basis to ensure that it's position is at the ideal position (which changes as the clutch wears out )

The net result is that during shifts the pedal only moved about 3".... and shifting could be done extreemly quickly.

[Slammed]

please explain dubble clutching?

[PrecisionBoost]

I will start a topic on double clutching to avoid messing up this post.

Basicly it's pretty simple....you just remove the bolts on the differencial cover, use this KM520 tool and pop the old diff out.

Then you do the same on the other tranny (final drive gear and all ) and switch them and reinstall the differencial.

If the two are sitting side by side it should take about 10 minutes.... but the problem is the stupid tool... which looks like this.....

[kinkyllama]

Also me, my gf, and my mom learned stick on my car.

Ahhh.... now the real reason for killing the tranny comes to light

Double clutching can be done super quick if the pedal travel is minimized via an adjustable bracket.

Basicly the bracket limits the movement of the pedal such that it barely disengages the clutch...... then you don't have to move the pedal eight inches just to make one shift.

I read a build up on this modification several years back..... basicly they adjust the unit by putting all four wheels up on a hoist.

Then they put the clutch in, put it in gear and slowly let out the clutch until the wheel starts to move ever so slightly (indicating the point where the clutch is touching the flywheel)

They mark this, install the bracket and then test it.

They push the pedal down until it bottoms out on the bracket and ensure that the wheel doesn't spin..... then they adjust the screw to move the bracket up (while clutch is fully depressed ) until the wheel starts to spin slightly..... then they back the screw off two or three turns.

I belive they also adjusted the rebound... since in most cases the pressure is taken off the master cylinder well before the pedal comes back to the normal rest position.

They did say that the clutch bracket should be tested on a regular basis to ensure that it's position is at the ideal position (which changes as the clutch wears out )

The net result is that during shifts the pedal only moved about 3".... and shifting could be done extreemly quickly.

Lol....yep! The gf (errr...ex actually) probably didnt hurt a thing. With my 6 puck clutch and 1200lbs presspure plate she got it on her first, second, third, ect...trys. Sadly she couldn't figure out the clutch on any stock car after me trying to teach her for nearly an hour. I think she was ment to be a tuner!

Anyways, that'd be pretty damn cool. But since I dont have much experiance with that kinda stuff yet I'll wait for you to do it and I'll copy it.

Basicly it's pretty simple....you just remove the bolts on the differencial cover, use this KM520 tool and pop the old diff out.

Then you do the same on the other tranny (final drive gear and all ) and switch them and reinstall the differencial.

If the two are sitting side by side it should take about 10 minutes.... but the problem is the stupid tool... which looks like this.....

Well damn, do you get the tool from GM? Do you know off the top of your head the price? ....Any other methods available?

The shop I take my car to won't touch the differential...so there pulling the tranny and putting it next to my new one, I'll swap the differentials, and then they'll install the new tranny. It's kinda lame but its there policy. I wish I had the time to do the pull and install the tranny all myself but I dont have much time right now and I want this done sooner than later, plus I dont have anyone around to help me if I screw up.

Danny

[PrecisionBoost]

I've looked around and I can't find one anywhere....... and I haven't checked the local dealership yet.

I was going to make one out of some plate material.... I figure it shouldn't take more than a couple hours.

Basicly I have to take my spare F16 transmission into work so I can design the tool with the tranny right there.

Once I make the tool I will probably end up removing the differencial and sending it down to one of the sunbird guys who makes limited slip plate type differencials.

He figures he can make them for about half of what Quaife wants.

After I make the tool I can send it down to you in the mail and you can just follow the steps I lay out (since I will take pictures )

chris

[kinkyllama]

I've looked around and I can't find one anywhere....... and I haven't checked the local dealership yet.

I was going to make one out of some plate material.... I figure it shouldn't take more than a couple hours.

Basicly I have to take my spare F16 transmission into work so I can design the tool with the tranny right there.

Once I make the tool I will probably end up removing the differencial and sending it down to one of the sunbird guys who makes limited slip plate type differencials.

He figures he can make them for about half of what Quaife wants.

After I make the tool I can send it down to you in the mail and you can just follow the steps I lay out (since I will take pictures )

chris

Cool. When will this be done do you think? I'm waiting on this for my car to be running, I'd need it by next Monday otherwise I might just try to buy one.

Sorry I feel like I always push you and I know your busy...it's just if I dont get my car back soon I might go insane.

[PrecisionBoost]

Ok..... so I'm finished..... it took me about 2 hours including the time to make the tool required to remove the bearing retainer on one side.

I was about 90% through removing the retainer when the 3/8" socket started to give way and spin..... so I did what I should have done in the first place and went back and welded in a nice big 1/2" socket.

So I would estimate that 3/4 of an hour was spent waiting for welds on the tool to cool off and the differencial removal in itself took about 15 minutes ( even with all the pictures I was taking to document the procedure )

Needless to say I think I could have two differencials swapped between cases in less than an hour.

My next post will go throught the making of the tool.... which is beyond some of your abilities but I figured I'd show it anyways.

For those who can't weld.... well you will just have to find someone to weld it for you or buy the GM tool ( KM-520 ) from a dealership.

If someone wants to edit this and copy the content over to a how to ( do not move it from here!!! ) I have no problem with that.

I'd do it myself but I've got a million things to do.

[PrecisionBoost]

Ok.... here is the tool required to remove the differencial on any F16/F20/D16/D20 transmission found in Daewoo, Opel, Holden and Vauxhall vehicles.

First off get some 1.5" wide flat bar (mild steel is fine) that is about 1/8" thick.

Cut the first piece 4" long.... and then make two other pieces of equal length so that the other diagonal dimension is also 4"



Then you take the long 4" piece an place it on top of the bearing retainer ring and mark out where the teeth are so that you can cut those sections out.

Also mark out lines where the teeth end to give you an estimate of how far down to cut with the hacksaw.



next you cut out the grooves and use a file to clean things up and adjust the size if needed.

Ensure that the piece drops down on both sides without too much trouble....you don't want it loose but it's ok to be a little sloppy.



Next you take the smaller pieces and lay them out so that you can mark the teeth in the same method you used for the big piece.

Ideally mark the small pieces #1 and #2 and make corresponding marks on the large piece so that you don't get them mixed up when it's time to weld them together.



After you cut out the notches ensure fitment and have the parts welded together ensuring that the position marks are lined up correctly.

When welding is finished and it has cooled down test fit it into the bearing retainer.

If it doesn't fit adust accordingly with a file... it's not neccisary to look good... but a good fit with square edges is important (so don't round edges)



After ensuring fitment I drilled a hole in the center and welded in a heavily worn 3/8" drive socket..... which was a mistake since it was too warn to take the force from the breaker bar and impact wrench.

Here is a pic with the 3/8" socket...... after failure I went back and welded a much thicker 1/2" socket in place... which held up great.

[PrecisionBoost]

Ok..... tool is finished.... lets get onto the easy part.

First off remove the differencial cover on the bottom of the tranny..... allways note the position you are putting the tranny into on the floor.... use blocks of wood to ensure that parts are not bend.... take care with the input shaft as it stick out just past the edge of the casing.

This diff cover has a seal on it..... replace it if you want..... but it's easy to get at so I would probably just use some high temperature RTV silicone to seal it up when reassembling the differencial case.



Next is the notched bearing retainer..... first off note the position of the retainer plate holding the notched ring in place.

Ideally take a center punch and lightly tap in a dot into the notch that is dead center in this retainer plate so that you can see it's position during reassembly.... ideally that dot will end up in the exact same place.... but it is possible to be off one way or another by a few notches depending on how the bearings seat.

As well take a felt and mark the edges of the retainer plate on the tranny as it has a small adjustment in postition that should be watched upon reassembly



Now that the retainer plate is off use the tool I made above to remove the bearing retainer ring.

It's a tough thing to remove (at least it was on mine) so I suggest the use of a nice long breaker bar and an impact wrench if you have one.

Ideally this should be done with two people..... I did it by myself with a great deal of cursing.... as it seemed to go nicely for a half turn and then get really hard to move for a 1/4" turn.... I turned the first two turns with the breaker bar (sometimes smacking the breaker bar with a rubber malet ) and then I switched to an impact wrench for the last bit.



After removal I put it back in and turned it in 1/16 of a turn just so that the differencial had something to rest against when I removed the plate on the other side.

Speaking of the other side...... flip the tranny over and remove the bolts on the other retainer



After the bolts are out I suggest lightly tapping on the retainer with a rubber mallet to rotate it slightly..... this will loosen it up enough that you can remove the cover with light prying using a screwdriver..... in my case it took one small pry with the screwdriver and then it came off by hand fairly easily.




Finally remove both retainers and carfully slide the differencial out of the tranmsission case through the cover plate hole.