DIY LSD install?

[Buzz Skyline]

I'm a do-it-yourself kind of guy. I like to do all my own car work whenever I can, which is a surprising amount of the time.

I have an OBX LSD on my shelf, with the upgraded Bellville washers already in, that I hope to install (or have installed) soon.

Does it make sense to install an LSD on my own, or is it foolish?

Have you done it? If so, how did the backlash adjustment go?

[Tamra]

We did it on our own. We linked to a few helpful threads in our post, here (http://thefactoryfiveforum.com/showthread.php?14362-Picked-up-our-STI-hybrid-swap-donor-today!&p=172415&viewfull=1#post172415). Rasmus also posted a bunch on his thread recently too, I think.

It took us about 5 hours, including swapping out the washers. We had never done anything like this before. With the FSM for guidance on the backlash, it didn't seem too bad.

[Jaime]

I did it.

I didn't think it was that bad - if you don't change the ring and pinion the only unusual tools you need are a dial indicator and stand. Mine's been go carted several times without issue.

[thall818]

I just did mine last Saturday. I rebuilt my OBX, but had my machine shop press on new bearings and transfer the ring gear. He only charged $40 and I just didn't want to mess with it. I had never had a transmission open before. I would do it again.

I have set backlash at least a couple times on the bench but without a dial indicator. I will be getting a dial indicator and setting it properly before I install. The backyard method just isn't giving me that warm fuzzy feeling.

[Buzz Skyline]

Thanks everyone. I think I'll give it a shot based on the positive experiences you all had. I guess I'll be buying a dial indicator too.

Best,

Buzz

[Hindsight]

Amazon has nice ones for cheap. Dont forget a mount.

[Buzz Skyline]

I think I'll ask Santa for one with a mount. I'll just have to send her (ahem) a link to the right Amazon page.

[Jaime]

Make sure to get this type:

36188

You can't position the standard type where the tip "pushes in" properly. The one above has an indicator tip that move from front to back instead of in and out.

[Buzz Skyline]

Thanks, Jaime! That would have been an annoying problem.

[Quiny]

I did the LSD myself, not too bad. I agree setting the backlash and bearing preload is the most technical part. I used a standard dial indicator but I wish I had the other type. I have go karted a few times and it seems to work, doesn't make any horrible noises and doesn't leak. Time will tell. Be sure and use the recommended sealant or equivalent on the case. The only other tip I can give you is to count the # of rotations when unthreading the side seal housings. They may end up different but at least you have a ballpark. Also when setting preload and backlash leave out the o-rings and seals in the seal housings until you get the settings right. You can then mark the case and count the turns remove them install the seals then replace. It is too difficult to get a good feel for the backlash with the seals in.

[Hindsight]

I'm getting ready to do my Quaife install. I've read all the posts here and read and re-read the FSM, but the FSM is a bit confusing to me.

Is this correct?

1. To check the ring gear backlash, you insert inner axle stubs in each side of the transmission, then rotate them in opposite directions will noting the reading on a dial indicator that is contacting the ring gear through the oil drain hole. For anything outside the proper range, you correct it by tightening or loosening the side carriers.
2. Any issues found with the tooth contact position (of the R&P) need to be fixed by changing the pinion height washer. The side carrier adjustment has no impact on this.
3. There is nothing else to check and adjust

Also, has anyone who used the same R&P but just swapped out the diff for an LSD had to adjust the pinion height washer? The FSM discusses it but doesn't show a clear picture of where it is or how to adjust it and I'm not seeing that covered in any of the posts here (unless I'm missing it).

Thanks in advance.

[Jaime]

To check backlash - hold the output shaft and move the top axle stub back and forth. The total play without turning the output shaft is the backlash. You won't get the stubs to turn relative to each other by hand with the Quaife.

[Hindsight]

Thanks Jamie, I'm not sure I'm following though. When you say to hold the output shaft, are you taking about the shaft at the rear of the transmission that the 2WD coupler is installed to?

Also, it really doesn't seem like there should be any reason to check the teeth contact pattern, since the pinion hasn't been changed. I mean, it's not a bad idea to check it but if only the differential is changed, it shouldn't change the pinion depth or require pinion depth adjustment no?

[STiPWRD]

Where is a good place to buy a Quaife LSD for a wrx 5 speed and how much do they typically cost? Are any other brands highly recommended? After some thought, an LSD seems like a must for a high horsepower 818. I too would probably install it myself.

[Jaime]

Thanks Jamie, I'm not sure I'm following though. When you say to hold the output shaft, are you taking about the shaft at the rear of the transmission that the 2WD coupler is installed to?

Also, it really doesn't seem like there should be any reason to check the teeth contact pattern, since the pinion hasn't been changed. I mean, it's not a bad idea to check it but if only the differential is changed, it shouldn't change the pinion depth or require pinion depth adjustment no?
Yes, hold that.

I changed my ring and pinion, so I needed to check the engagement pattern. If I were keep the R&P, I would probably check it while I was in there - but I'm sure you'll find different opinions.

[Hindsight]

Thanks Jamie!

STiPWRD: A Quaife is around $825. I agree it is a must which is why I got it. I didn't want to spend the money, and I don't want to spend the money on the race logic traction control system either, but I've done things the wrong way enough to know that for something like this where fun and safety are involved, you do it right the first time and live to enjoy it again and again.

There is a vendor here that sells them called The Race Line. My experience with them was mixed - very friendly, honest and well-meaning but not very proactive on communication when the diffs went on back order for half a year. Apparently there are a number of them in stock now so you probably wouldn't experience the same issue I did. You can Google Shop them as well. There are two versions - the cheaper of the two is for use with the male stub axles and I believe (please verify before ordering) this diff will drop into the earlier model transmissions with the male stubs, but you just need to change out the axle stubs if doing this. The Quaife part number for this is QDH3Y which is what I got.

[STiPWRD]

Thanks Hindsight, I think I need QDH1Y, which has the male stubs for use with the female axles. I prefer the male stub transmissions so I don't have to drain out the trans fluid if removing the axles temporarily. Plus I already build my FFR axles with female CV joints. $825 seems very reasonable so I'll try to contact The race line. A "quick" google search came up with about $1200 shipped for the cheapest I could find.

[Hindsight]

The version you want costs more.... Gotta figure out if the no oil drain ability is worth $400 ;)