Ok - so I called the dealer. They say that in order to install the limited slip correctly, the speedometer drive gear needs to be changed? The dealer was stating that this was in his paperwork but didnt know how or why it would need to be changed? Can someone give feedback on this?

WTF!?

Exactly what he ^ said. Hadn't heard of this previously, and it doesn't make sense since the final drive and gearing isn't changed. Won't go so far as to say it's bogus, but I'd require some logical rationale before I'd consider believing it. :eyebrow:

Im not sure but the dealer who im dealing with ...hes a cool guy. He didnt know why but he was reading what was on the paper (or what was on the computer screen). There is no way he was making it up because this dealership isnt like that (and i cant say that about the other dealers I have been to).

I think your dealer is on the up and up. I noticed on LSD install kit from Sparks that it says "Excludes shims and speedometer drive gear", so it seems to me that it needs to be replaced.

It's fine if the instructions and Toyota/Scion/TRD/Quaife state it needs to be changed, but we simply need an explanation in order to understand WHY.

the speedo drive gear is on the differential assembly. its a plastic gear that has to be boiled in water to be removed without breaking it. so most dealers will just sell you instead of messing with trying to swap out the gears. its a reliability thing, instead of the tech risking a broken gear and the shop having to eat the bill for a new gear they just sell you one to begin with. it makes life easier but you can do it without a new gear if your carefull.

hope this helps, http://trdsparks.com/install/PTR39-21070inst_tC.pdf

hope this helps,
Yes, and thanks! :D

That's an easy to understand explanation that makes perfect sense.

Sounds to me that if someone took their time there would be no problem.

Two ways to do this......

Spend the time pressing off the old bearing which ruins it to get the speedo gear, which BTW comes right off, it fits loosely.

Second, buy a speedo gear and not have to mess with the original diff. The $35 for the diff gear is offset by the time wasted getting the old one off.

The thing that worries me, the TRD LSD I'm installing had a 2.40 MM shim with the stock diff, I had to use a 2.05MM shim for the TRD/Quaife. That wasn't a problem for me, but if the TRD's are gonna be a little wider and you OEM Shim was 2.30mm, smallest is 2.00MM, might have to do some fancy work.

http://i107.photobucket.com/albums/m307/bonespec/Transmission/Scion%20tC/P1180006.jpg

http://i107.photobucket.com/albums/m307/bonespec/Transmission/Scion%20tC/P1180012.jpg

http://i107.photobucket.com/albums/m307/bonespec/Transmission/Scion%20tC/P2230007.jpg

Also you can eliminate about 30-40 steps of the 121 steps. Like a Honda I pulled the gearclusters and shift forks out together. Getting them back in requires a third hand as the diff has to be lowered in with the gear cluster.

The hardest part has been getting 5th gear back on. The synchro assembly like to come apart. NOT FUN!

Two ways to do this......

Spend the time pressing off the old bearing which ruins it to get the speedo gear, which BTW comes right off, it fits loosely.

Second, buy a speedo gear and not have to mess with the original diff. The $35 for the diff gear is offset by the time wasted getting the old one off.


makes good sense to me. nice to hear from someone who's actually done this. plan on doing it myself when I have the finances.

^ but how much extra will it cost to get the parts so it will be less time consuming and get a finished product that you know will be 100% correct?

how much do you think all tis is gong to cost you?

^ but how much extra will it cost to get the parts so it will be less time consuming and get a finished product that you know will be 100% correct?

well he said the drive gear cost 35 bucks. so is it worth getting off the bearing just to save 35 bucks?

I think its a smart Idea just to buy a new one. then if you want later you can press out the bearing and remove the speedo drive gear and sell to some one for 20 bucks and get some of your cash back.

oh jeze - so just $35 bucks? Sounds like a no brainer then. That should be one of the parts included in that install pack for the lsd then. The dealer notes say it needs one ..why the heck is it not included then?

^
cheap bastages

Also if you buy the speedo gear, you always have the option of reinstalling your stock diff and sellign the Quaife......

^ ha - if you are doing the install maybe ...hehe.

Well, if your having a dealership or any other garage, it will take 5-7 days. You won't know what shims your gonna need until you try putting it back together. Then they have to be shipped in from the Los Angeles, California main parts warehouse.

Well, if your having a dealership or any other garage, it will take 5-7 days. You won't know what shims your gonna need until you try putting it back together. Then they have to be shipped in from the Los Angeles, California main parts warehouse.

which isnt something that could be ordered in advance?

18 shims at $6.30 a piece, $113.40 + tax.

Then returning for credit, something you can do via internet sales.

does anyone have the 121 step process that bonspec mentioned?