OBX LSD Discussion

[DoubleD]

First, I would like to state that I am not trying to put our vendors on the hot seat here. I have purchased from our two main vendors numerous times and I am not biased, I will go with whoever gives me the best overall value, that said:

I am looking to install an OBX LSD in my A523 in my 92 IROC R/T next season.

I know both of our vendors offer similar units with upgrades automatically. Both offer complete machining to fix the down falls of the unit and upgraded washers. The FWD one does not include upgraded bolts, are upgraded bolts a neccessity?

The FWD unit comes with the bearing installed (this is a bonus for me as I dont have the tools to press on my own bearings)
Also the FWD one comes with the axle housings honed, ive read that this is an issue, is it common for the axles to not fit w/o honing here too?
There is a price difference here thou small, but I am really not worried about that, im more interested in quality and availability.

Ive read the details but what all does it take to install this unit? Mostly a dial indicator and proper shims?

What are people experiences with this unit and the buying experience?

I am no trying to start a fight, I just want a quality product that will stand up the the abuse my car will put on it. (500+whp)
Thanks

[jonnymopar]

I also have done a fair amount of business with our two main vendors as well, so I'll chime in.

When I purchased mine, it was from TU. At the time, I was purchasing a clutch from them, so I decided to buy everything at once. I did get the optional clean up with new washers/bolts. They did a great job cleaning up the inside, and they even included the old hardware with the unit. However, I did have to hone the driver's side bore. I tried two different axles and neither fit. It was easy to do and didn't take long. If you need to do that, I'd recommend disassembling the differential so all of those fine shavings can be completely cleaned out after you're done.

As for the quality of the unit and other matters independent of vendors... it is what it is. There are reasons that it doesn't cost what a Quaife does. But, plenty of people have thrown large amounts of power at it and not broken it, so there you go. Two things that I noticed with mine (granted, the differential *does* work):

1. The main gears on mine have the helix cut backwards. I compared it to an older OBX unit and also to the Quaife, and in both comparisons, mine were cut the wrong way. I got into a whole discussion about it and I ended up just saying f*** it, I didn't spend over half a grand on a bench ornament. So it's back in there as-is. We'll see what happens long-term.

2. There seems to be excessive backlash in mine. This is comparing it to when my transmission was a stock, unknown-mileage 555. Now, I'm running a new, solid-hub clutch, the slop has been taken out of the input shaft bearings, and the differential is spinning on brand new, properly preloaded bearings. Even still, the backlash is much more noticeable than stock. It's a bit awkward driving at low speeds. This is with the same transmission, same axles, and same engine mounts as before. This may have something to do with the backwards gears, or just overall mechanical tolerances inside.

Last but not least, regardless of what the "warranty card" says, there is NO WARRANTY on this LSD. OBX will not return emails or phonecalls. Search around online and find out how people have made out trying to deal with them.

Now, with all this said, my Daytona is in the parking lot right now. The OBX is in it. In about an hour, I will get into the car, drive down the road, approach the on ramp, tear through the on ramp without breaking traction on my inside wheel, and when the road straightens out, I will mash the gas and obliterate both tires, and things will be ok. The differential does work. It just works like a $500 unit, not like a $1500 unit. If I had to guess, I'd say I'm only putting ~275hp through it. People have used the same part behind twice that amount of power, even sheared their axles off inside of it, and it was still ok after.

[Chris W]

I also have done a fair amount of business with our two main vendors as well, so I'll chime in.

When I purchased mine, it was from TU. At the time, I was purchasing a clutch from them, so I decided to buy everything at once. I did get the optional clean up with new washers/bolts. They did a great job cleaning up the inside, and they even included the old hardware with the unit. However, I did have to hone the driver's side bore. I tried two different axles and neither fit. It was easy to do and didn't take long. If you need to do that, I'd recommend disassembling the differential so all of those fine shavings can be completely cleaned out after you're done.

We have installed several of these units locally which never required honing. We have shipped over 100 in the last couple of years and have never received feedback about the axles not fitting. Would like to hear from others besides yourself who may have experienced this issue. From this point forward though we will test fit both sides with an axle to make sure there are no installation issues. If required we will hone to insure fitment.

Thanks for the info!

Chris-TU

[turbovanman²]

I've had mine in since around 2006 and I've beaten the living shitt out of it. Its showing some wear at the teeth but that's more than likely due to all my grenaded trans and the sintered oil flowing thru it. I never had to hone anything for the axle shaft to fit BUT the one bearing race wouldn't fit without splitting, so I had to sand the unit down. I changed out the bellvelle washers after a few years as I saw, like eveyone else, they were broken and in fact, I welded them back together at one point. I never tapped the threads but did after I took it apart for the first time. Hope that helps.

[ajakeski]

I recently bought a couple OBX limited slip differentials through a group buy with my local SDAC Chapter.
I was prepared to clean up and finish the machine work inside the diff. When I opened it up, I found a few cracked washers, but the machine finish inside was really good.
No clean up was needed.
I changed out the washers and reassembled the diff with new bolts.

[Chris W]

Regarding warranty, we have only had 2 issues that I can recall. One was a customer installed service kit which we were unable to assist with and the other was a unit we serviced which had damaged gears. OBX just swapped it out for a new unit. They even picked up the tab for return shipping from our shop. We also service Mazda Miata units and they don't seem to have the same issues we find in the ones for our cars.

OBX Bellville washers are HORRIBLE. I would never install these LSD without swapping them out. That's why we include the originals so the customer can see how crappy they are.

Chris-TU

[jonnymopar]

We have installed several of these units locally which never required honing. We have shipped over 100 in the last couple of years and have never received feedback about the axles not fitting. Would like to hear from others besides yourself who may have experienced this issue. From this point forward though we will test fit both sides with an axle to make sure there are no installation issues. If required we will hone to insure fitment.

Thanks for the info!

Chris-TU

Before I took a hone to it, I made sure it wasn't something funny with the relationship of the gear splines versus the bore. I test fit the axles into the outer piece only, separate from the rest of the diff. That's when I narrowed down that it was binding there. Again, it wasn't a big deal, plus I'd heard about others having the same problem with OBX differentials in general, not specifically the Chrysler/Mitsu part that we use.

OBX Bellville washers are HORRIBLE. I would never install these LSD without swapping them out. That's why we include the originals so the customer can see how crappy they are.

YUP! Deformed and/or cracked from the factory!

[bfarroo]

I has to hone the passengers side on mine. From what I remember I pre fit the axles before putting on the bearings and they were a little tight but fit. After pressing on the bearings the passengers side would no longer fit. I tried turning the axle a spline at a time as some had had success with that but had no luck. 5 min with a hone cleaned it up and haven't had any other issues.

[4 l-bodies]

I has to hone the passengers side on mine. From what I remember I pre fit the axles before putting on the bearings and they were a little tight but fit. After pressing on the bearings the passengers side would no longer fit. I tried turning the axle a spline at a time as some had had success with that but had no luck. 5 min with a hone cleaned it up and haven't had any other issues.

Yeah Bradd,
I had about the same results as Benji. Bought mine from another source than our vendors. Had to hone just one side. I took mine apart and did lots of deburring. I also bought hardware kit and installed. Like others have said, it's certainly no Quaife (quality wise), but it is also less than half the cost. Unit worked really good.
On another one, I slipped axles in both sides of unit before tightening the allen head fasteners, assuring proper alignment. That unit I did not need to hone either side.
Todd

[Pat]

Yeah Bradd,
I had about the same results as Benji. Bought mine from another source than our vendors. Had to hone just one side. I took mine apart and did lots of deburring. I also bought hardware kit and installed. Like others have said, it's certainly no Quaife (quality wise), but it is also less than half the cost. Unit worked really good.
On another one, I slipped axles in both sides of unit before tightening the allen head fasteners, assuring proper alignment. That unit I did not need to hone either side.
Todd

I did the exact same thing as Todd...bought a unit from someone, rebuilt it, deburred it, new washers/bolts, pressed on bearings, slight honing and it's worked great on a mid 11 second, full weight Shadow that ran thorough Hot Rod's Drag Week, sees lots of street/commuting time, a fair amount of beatings and an occasional autocross. It's an effective unit in my view.

[jonnymopar]

On another one, I slipped axles in both sides of unit before tightening the allen head fasteners, assuring proper alignment.

I'm glad you said this! I forgot to throw that one in there. If you have an extra set of axles or a couple of loose inners, doing this will save you a potential fight in getting the axles in once the trans is already installed.

[shmedley]

any particular hone you guys have used?
I got mine through a local chapter group buy and none of my axles will fit in it

[jonnymopar]

This one did the trick for me. I set the spring pretty tight and just oiled the hell out of everything while I was working on it.

http://www.autozone.com/test-scan-an...ke/531707_0_0/

[bfarroo]

I think the one I used was a brake hone of some sort. Didn't take much. As others have said for the price the unit does the job it was intended to do.

[Reaper1]

I have a slightly tough time getting my passenger side axle to go into my OBX. I have to whack it so it will slide all the way in. (Could that sound any more dirty!? Lol) I got mine around 2006-ish, though.

[Ondonti]

I have a slightly tough time getting my passenger side axle to go into my OBX. I have to whack it so it will slide all the way in. (Could that sound any more dirty!? Lol) I got mine around 2006-ish, though.

Same time period, nothing was wrong with my washers. I have to reclock both sides of my axles until they will fit in. Have not removed it from the current transmission that its in for maybe 7 years. Didn't look at the time what might misalign without axle stubs in there when tightening the allen bolts.