in goes welded diff, and rearend blows up

[jesepes]

Ok, I put a welded center diff in my 92 awd talon and a short time later the rearend is smoking hot and making bad noises? My question is, was there something wrong with the rear end, or are welded diff's that tough on rear ends?? I noticed the problem after about 20-30 miles of easy (65mph) freeway driving.

 

[ACKERSON]

Probably just a coincidence. I've been running a welded diff for about 3 months no problems.

 

[i1nk83]

does your welded diff make noise and whatnot when your turning sharply?

 

[kyledykstra]

More than likely, as you locked both tires together, but the inside one has a much shorter distance to travel, so it's going to be hopping and skipping

 

[jesepes]

does your welded diff make noise and whatnot when your turning sharply?

No, there is no noise from the diff area, only from rear end area.

 

[98talonAWD]

with a welded diff you want to pay close attention to tire pressure too. that can help or hurt your turning and how badly your tires are worn. i've had a welded diff for 4 months and nothings wrong with mine. although the car hop's like a damn rabbit.

TIM

 

[LilGdsm]

I have a spool, same thing. You're wheels are going to hop or kick while turning, specially at low speeds since your front and rear tires are starting to fight against each other on the turn.

 

[jesepes]

are all of you guys daily drivers? Thanks for the help. I've disassembled the rearend now and found that all the bearings look a bit worn, but the pinion got extremely hot, I'm guessing from one of the bearings on it going bad. The gears look great, but I'm not sure how to accurately test the VC. I am going to search for some data on bench checking it out of the carrier. Do any of you have the Mitsu. mtx. manual?? I need some specs on rearend rebuild.


P.S. sorry i forgot to specify earlier that my center diff is welded and I still have a VC in the rear.

 

[GIXXER95]

I have a spool, same thing. You're wheels are going to hop or kick while turning, specially at low speeds since your front and rear tires are starting to fight against each other on the turn.

No, you DO NOT have the same thing. I may be relatively new to DSM's, but I come from a background in truck racing/rock crawling/ mud bog racing. A welded diff is affectionately known as a "LINCOLN LOCKER"

The end sum is the same as a spool for now, but LilGdsm's spool is'nt likely to go -ever
If you're running a welded diff, do yourself a favor and keep spare parts on hand.

Building a rearend takes specialty tools that you are not likely to have (or want to buy unless you're gonna build alot of them, you can limp through without most, but you know how it goes "having the right tool for the job" -so to speak)
It's not easy to get right the first couple times either unless you completely luck out. There are several key measurements like pinion depth, backlasy, carrier preload, etc... that are all quite relative to one another (you're working in thousandths, and one change affects the other measurement) and each change is another teardown/new setup with all the speacialty tools like a press, clamshell seperator, various pullers, pinion depth checking tool, dial indicator, calipers, diff spreader, etc... (do you have an inch pound torque wrench? )

If you really want to (correctly) tackle an axle-build though, I'd be happy to share with you what I know (I've built probably 15-20 axles and only 2 self destructed prematurely, I got the right tools though)

Believe me, you're better off paying someone REPUTABLE.

Oh, you say your gears look great, describe your contact pattern?

 

[jesepes]

No, you DO NOT have the same thing. I may be relatively new to DSM's, but I come from a background in truck racing/rock crawling/ mud bog racing. A welded diff is affectionately known as a "LINCOLN LOCKER"

The end sum is the same as a spool for now, but LilGdsm's spool is'nt likely to go -ever
If you're running a welded diff, do yourself a favor and keep spare parts on hand.

Building a rearend takes specialty tools that you are not likely to have (or want to buy unless you're gonna build alot of them, you can limp through without most, but you know how it goes "having the right tool for the job" -so to speak)
It's not easy to get right the first couple times either unless you completely luck out. There are several key measurements like pinion depth, backlasy, carrier preload, etc... that are all quite relative to one another (you're working in thousandths, and one change affects the other measurement) and each change is another teardown/new setup with all the speacialty tools like a press, clamshell seperator, various pullers, pinion depth checking tool, dial indicator, calipers, diff spreader, etc... (do you have an inch pound torque wrench? )

If you really want to (correctly) tackle an axle-build though, I'd be happy to share with you what I know (I've built probably 15-20 axles and only 2 self destructed prematurely, I got the right tools though)

Believe me, you're better off paying someone REPUTABLE.

Oh, you say your gears look great, describe your contact pattern?

Like you said "the end sum is the same as a spool". I know the difference between the two and know they function the same way. You appear to have underestimated me. So, to clear things up, I have all the tools available to me. I am an aircraft mechanic who works in an overhaul shop. I have every tool and an infinite amount more available to me including a full machine shop including a surface grinder with magnetic bed to aid in custom grinding all/any shims/spacers I may need to my exact specs.

Please do share what you know with me. Since I haven't done a rearend rebuild before I can't claim to know EVERYTHING about it. I have the general basics for setup under control. As far as conctact pattern on gear teeth goes, i don't really have the experience to accurately describe what i've seen. You could help me in this area. Maybe you could describe what it's supposed to look like and what it should not look like and then I can use your description to tell what my gear teeth look like.

I also don't have a spec for backlash and carrier preload yet. What are some general spec for those two tolerances? I plan to find what DSM's use, but knowing general specs is also helpful. Thanks in advance for you help.
-Jesse

 

[4pistons]

WHOA guys! A lot of misinformation here! On an AWD DSM a welded diff usually refers to the center differential in the tranny not the rear axle. I have never seen a welded rear diff on a DSM. That said, it does not lock your two rear wheels together so it is not like a spool. Your rear LSD is still operational and can differentiate the rear wheels.

jesepes, If your rear end is howling it's most likely due to running dry or worn bearings. But the welded center diff shouldn't have any effect on it.

FWIW I have been daily driving my '91 GSX on a welded center diff for 5 YEARS without any abnormal problems. I've even been autocrossing on it for the past two years.

Rick - '91 GSX

 

[jesepes]

Yeah what you said is what I was talking about, i guess it is kind of vague to those reading it as compared to those writing it, (sorry). Thanks for the info on your experience with welded center diff. I have that as well. On another note, i'm doing a rearend rebuild and am ready to put it together, but don't have all the specs/tolerances yet. I need them to finish the job. I'm calling lots of Mitsu. dealers tomorrow, the three I called today gave me the " we don't have manuals for cars THAT old." BS line. (Lazy bastards.) Anyway thanks.


**Edit** I edited my original post to say "in goes center welded diff, and rearend end blows up"

 

[LilGdsm]

I meant a welded center diff will act the same as a spool center diff would.