S15 HLSD in my S14

[anyotherone]

First off, I apologize for not taking pics and doing a complete write-up. I am in the process of making a write-up complete with illustrations take from the FSM... basically almost everything you should need to know, just no pics from my install.

Overall, it took me and a friend about 4 1/2hrs to complete, including breaks, phone calls, a trip to the parts store for a slide hammer, and a 30min round trip to his house to use his air rachet. It would have taken half the time to do this if we had only planned ahead and made sure that we had everything we needed!

We installed this into my '98 S14 SE 5spd, that came without a VLSD or ABS.

We used the stock shims and the HLSD fit like a glove.

First impressions: I have more grip, I can spin both wheels, and I can even drift my car easier... though an HLSD isn't the best choice of LSD for that.

I chose this over the S14 or Z32 VLSD and a host of more expensive options due to price range and the functionality of a Helical/Torsen vs. Viscous, Clutch type, 1.5way, 2way, etc. etc... which you can find debated in a dozen different threads. This car is my daily driver.

I haven't tracked this car yet, and everything else is stock or as it was when I bought it, right down to the crappy Kumho 711 tires. As I continue to mod the car it will probably see some auto-x or road-racing track time and then I shall see if I made the right choice!

~Cameron

[naed240sx]

sweet. I am so jealous. HLSD is the way to go for grip, and they last forever and are not as damn loud as clutch diffs. I was gonna get one, but went the cheap route and got a vlsd. So... Im assuming that you used the s15 diff outputs and the stock ring gear, but what did you do about the input shaft? The s15 one is too long, but the s14 shaft is too small of a diameter. Ive been curious about this for awhile. Anyways, congrats on your great pick of a differential. Let me know about my question.

[Dattebayo]

you know we are all jealous. I would use one just for how long they last. Its at least better than a J30 diff, like most of us cheapo guys put on...

[anyotherone]

You guys are naming all of the reasons why I went ahead and shelled out the 600 for this diff.

To answer your question naed240sx, I used the S14 input shaft... the only thing I used from the S15 were the output shafts and the actual HLSD unit itself. What makes you say that the S14 would be too small?

[naed240sx]

I guess that is only a problem for the s13? I know that the s13 input shaft is 30mm in diameter, but the diff requires a 31mm. So if I did this swap I could use an s14 input as long as it was non-abs?. And stock shims huh? Ive heard horror stories about backlash and having to get gear shops to use dyes to get proper gear mesh, etc, etc, etc. I bet it pushes through the corners amazingly well. Everyone seems to think that kaaz/cusco is the way to go, but helical is way better for grip

[f1seb]

Where did you purchase this LSD Im interested in it as well. Will it hold 350+whp?

[AJ1356]

dude, you suck ,,lol.. if i could find a s15 HLSD then i would not have had to make soo many custoom things to get the damn speedometer working.

[anyotherone]

I got the HLSD off of Ebay... keep watching, they pop up fairly often. Just beware, and ask the seller plenty of questions to make sure that your getting the right item. Just make absolutely sure that it comes with s15 output shafts!

I'm not sure about how much power it will hold... my guess is as much or more than stock vlsd's.

[anyotherone]

Yes, I would argue that this is the best street/grip option out there.

I haven't noticed any unfamiliar noises so far... though my car rattles a lot as it is. It cost half of what a Quaife would have cost me too.

Just a side note: This is not the best choice for some of you guys. A clutch-type LSD will do a better job of locking both wheels together on launch, or for drifting... but this same characteristic causes understeer in grip-driving situations; because the clutches lock-up and both wheels go the same speed. At least, this is my understanding.

[TachyonS14]

Pretty cool man. What can you tell us about the gear ratio change if any? Are your rpms lower or higher in any gears? If so, do you find them to work better with the KA then the stock diff? Details man details!

[fatboy]

when adjusting backlash,

I guess that is only a problem for the s13? I know that the s13 input shaft is 30mm in diameter, but the diff requires a 31mm. So if I did this swap I could use an s14 input as long as it was non-abs?. And stock shims huh? Ive heard horror stories about backlash and having to get gear shops to use dyes to get proper gear mesh, etc, etc, etc. I bet it pushes through the corners amazingly well. Everyone seems to think that kaaz/cusco is the way to go, but helical is way better for grip

when adjusting for backlash, you get 2 new pinion bearings. ream one out a little bit for you test piece. and when you find out what you need (shims), then you press in new unreamed piece. i know personally i keep many different pinion bearings cause i do lots of rearend work

[swwifty]

awesome! I have a S15 LSD on the way with brand new output shafts. I'm going to be installing it soon as well, so I'd be curious to see your write up. I'll be installing it also in a S14 without a stock VLSD or ABS. I'll probably do a full write with pictures as well. Did you need to replace any other parts on the diff? (like seals or anything else, I know fluid obviously) I need to look at the FSM too.

[anyotherone]

Just make sure that you have a new diff cover gasket. I used silicone gasket because I was going to have to wait for any local places to order the oem one, but now I think it has a little bit of a leak. I'll probably replace the fluid, that gasket and some of the bushings some time in the next few weeks.

[Dattebayo]

The gasket is easy as crap to get, I dont know what you are talking about...

Advance Auto parts can get it to you in less than 2 days! And its a felpro gasket too! Where did you check?

[anyotherone]

There aren't any advance auto stores in the DFW metroplex area.

I called Autozone and O'Reilly auto... and two Nissan dealerships, but I already had the diff apart and it was 4pm on Saturday.

I'm not saying I couldn't get the gasket, I just couldn't get it in my time-frame.

[anyotherone]

Actually, O'reilly sucks... they didn't even have a parts listing for it in their catalog or computer.

[Dattebayo]

You shouldnt use silicone for a diffy, I believe the gear oil breaks down the material or something... Besides, the gasket is the same for many different nissan cars since many of them had R200 style rear ends.

Never rush an installation no matter what.

[anyotherone]

Thanks.

[Dattebayo]

Sorry, didnt mean to sound preachy, Its just that alot of people dont know about it.

[anyotherone]

No it's cool.

I seriously would not have done that... but when I got to looking at bushings and stuff I realized I was going back in pretty soon anyways, so I sort of winged it. It's fine for at least a little while.

I completely agree with you on not rushing installations, or anything that has to do with work on cars. Rushing only leads to mistakes and those mistakes can be costly.