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"Death of a Differential" AKA guide my rear end revamp

5K views 35 replies 9 participants last post by  mutantcolors 
#1 ·
Bought an 82 P type at a good price on the suspicion the diff was going out.

Suspicion has been confirmed. Ring and pinion are okay, bearings need redone. Seems someone botched an attempted rebuild and just tightened everything down as much as possible.
LSD clutch components also appear to be done for.

It's a 3.73. Do I:

- Spend several hundred on a rebuild on a diff with worn out limited slip
- Throw even $500 more at it if I'm lucky to add in some form of LSD
- Hunt down a used diff (preferably in the 4.10 range)
- Try to yank one off a pick-a-part Toy of whatever model (front diff parts off a 4WD anyone?)
- Other?

Let's figure something out.
 
#2 ·
It will be difficult to find a 3.73. A 4.10 diff should be easier to find used and would be a budget solution. If you have money, a rebuilt 3.73 LSD would be very nice.
 
#3 · (Edited)
There's a used 4.30 LSD near me for $250. Tire spin in first and cruise at 4500? Or good idea?

I can afford to redo the 3.73 but I am a miser at heart.

To quote myself:
"BEST case scenario: the stock 3.73 LSD is rebuildable, and I take my sweet time hunting down a 4.10 LSD or one I can retrofit. Until such time the 3.73 stays in the Supra, then the 4.10 goes in the Supra and the 3.73 goes in my Xtracab pickup. As per our phone convo, fingers are crossed for the rebuild. In spite of "blowed up" he also used the words "not that bad" two hours later.

I have to remind myself I landed the Supra in a fluke of researching ways to freshen/liven up my truck."

So the 3.73 stays with me either way.
 
#4 ·
These cars are rare and valuable. Don't take the path of the miser.
 
#6 ·
I appreciate that. I'm not going to take the path of cheap and shitty, I simply mean cost effective. Cost effective is in my blood haha. If, for now, I can grab a 4.3 and be done with it I can also take my time rebuilding the 3.73 with the best parts I can find.
 
#5 ·
a 4.3 is fine on highway, i barely notice a difference between the 3.7 and 4.3 to be honest. other than looking down in 5th and see im cruising at like 2000rpm lol.

source the parts first and if the bearings are easy to get...you might also have other issues that were caused by said fucked up bearings. not sure how you fuck up putting bearings in. you take the old ones off and press new ones on...the issue is backlash and pinion tension, both relate to how they're shimmed.

my 8inch diff bearings were only available through toyota (they have a patent) and were 100bucks ea...but in USA they're 45 each. if you have a FSM and the parts, a good mechanic should be able to do the overhaul. with running into a lot of problems and wrong parts, took a friend of mine and I, a day and a half to do my diff with a FSM and checking everything 80 times...and i didnt have any shims, had wrong bearing and went on a wild goose chase to find a crush sleeve.
 
#7 ·
I wanted to replace my 4.10's with a 4.30 until I found that Erin's car next to me @ 66 MPH sounded like she was in 4th gear! If I went to 4.30's,a taller rear tire may be in order.Those would make really good 1/4 mile drag racing gears,for my car anyway.

You could toss the 3.70's in the corner and spring for the 4.30's and bolt it in.Rebuild the 3.7's for a ROAD TRIP in the future.

From what I read,it's difficult to find the correct parts to do it right. The ring and pinion may be OK: it was in gear oil and the bearings were not.LSD is cooked?That's easy. It's the set up and shim- shuffling that will give you fits,from what I have read and seen on Eric the car guys You Tube channel.
I'll guess that the pinion bearing has been sloughing off bearing bits for a while.

I'm on my 3rd(Used) differential.
Dumb-ass me,I threw away the 4.10 OPEN ,dammit.:eekfacepalm:

My second 4.10 LSD was a @#$!((**)screamer and Ray has it,now.
My 3rd one is tolerable:80% quieter.
I absolutely stole it for $100,2 years ago.

My mechanical skills do not include a diff rebuild.It would be a 'screamer' when I was through. The ONLY way I would attempt one is with a NEW R&P,that does not have wear patterns in the gears,already.

My differential is due for new fluid.Synthetic + additive and I don't care if I over fill it.
[URL=http://s514.photobucket.com/user/ddd228/media/temporary_zpsuhm6e53z.jpg.html][/URL]
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Notice the magnets on the fill/drain plugs.
 
#8 ·
Road trippin' is certainly in this car's future. Idaho is flush with mountain highways full of turns and no one watching :thumbsup:
$250 for a 4.3 LSD when I was quoted $600-800 to redo the bearings to get me back to basically an open 3.73...

I did see LSD rebuild kits for about $150 in parts.
 
#9 ·
I enjoy long road trips in my 83, not street racing. I do 80 or more with the 3.73 and the RPM's are way less than my original 4.10 and I'm sure it's better on gas. My engine would scream at 80mph before the 3.73
 
#10 ·
I will NOT be racing this thing, let me get that out there haha.

The 3.73 may very well just stay in the car, but it'll HAVE to have a bunch of work, and I'm looking at like $1200-1300 if I want it fully redone. And one way or another, I want to get a limited slip in my truck too, so I am leaning toward that used 4.30. I have feelers out on other diffs as well, but I think $250 for an operable LSD is a pretty fair deal.

I'd like to hit our junk yard but there's over a foot of snow on the ground with more coming, and we had a high of 8 degrees today. No thanks.
 
#11 ·
Now,you are looking for TWO diffs?
You want 3.73's for your truck and your Supra.
If you can go to taller tires on your truck,the 4.10's may do.
Used is WAY cheaper,if you can find a few.

WANTED: 3.73 LSD's (2 OF THEM) In the meanwhile,
Grab that 4.30 LSD and see if is NOT a screamer.

Too cold to crawl around on the ground for me. 8*? NO WAY.
I'll do the diff oil in my springtime.

You can choose what to do first, on both of your vehicles.
I don't have a heated garage to work in.
You are the latest drive line/diff guy this week.
 
#12 ·
No, I'm not after 2 diffs. The 3.73 in the Supra needs bearings and the LS rebuilt. The 4.30 would (maybe) go in the Supra (for now?) and if I want LS in my truck, I need the parts. It's an F code diff too, I've seen on more truck related forums, guys pop those pieces into their open diffs and are done.

Or I could rebuild the 3.73 for the truck. Right now it's like a 3.52 or some such. Winds up quite high on the freeway as is though. No interest in taller tires, it's 2wd, and my favorite places go from 2wd roads to pack trails. Not much of a 4x4 guy. BUT now you can see why an LSD is desirable for my truck. I spent 20 minutes digging myself out to get to work Weds morning.

Pardon the possible duh moment here, but 5M powerband really kicks in higher up right, so my brain tells me a rather fun experience would happen through a shorter gear set like a 4.30 to get you into the zone quicker.
 
#13 ·
QUOTE:
Pardon the possible duh moment here, but 5M power band really kicks in higher up, right? So my brain tells me a rather fun experience would happen through a shorter gear set like a 4.30 to get you into the zone quicker.
AGREE!
That's exactly why I wanted a 4.30: LACK OF TORQUE.Wait for it... and wait some more.
I got past that after adding some intake mods.WAY better! Later, an '85 5MGE.

Comparing my last (car), big block Ford , I thought that the 5 MGE was totally lame for torque. True.
Fixed that.. and my 4.10's were OK,then.
I even thought of buying a high-stall torque converter to fix the lack of torque.

The 6,000 rippem's is fine,but it takes a long time to get there and the lower gear diff would be able to get past the lack of torque area to some REAL horsepower sooner/ faster.
The torque curve on our engines happens at 4 K?
Would you choose to cruise at that RPM?
No.

2,200 RPM is about right at your chosen high way speed,for our engines. Agreed?

You drive/cruise at 80?
You want the 3.73's to work,in your application.
Sure,the 4.30's would be better for acceleration,but it will hurt your MPG's on the high way,considering the engine speed.
You may wish for a 6th gear to mellow out the engine speed.
You won't need down shift to pass a Volkswagen/Geo/slow driver,with the 4.30's.


It has to be a balance of power and gearing to make you(and your engine) happy.
MPG'S? Lower RPM is better,usually. That's why there are overdrives:Just cruisin'.
I can tolerate the slight whine @ 50-60 MPH.
I'll never go back to an open diff, as I have seen snow in Seattle, B-4: I had to get to work!
I have also changed the spring's pre-load to compensate for the R.R tire spinning wildly out of control and left it that way for the LSD action. Better!

Snow? You get used to the ass-end swinging out to the right,but it's fixable if you create more load on the R.R. tire with spring pressure/load.
Ever driven a Corvette in the rain?
Jim knows.
 
#14 ·
No but this is winter number 13 in my truck ;) Spinny spinny. Hell, I can "peel out" after a light rain, and I have a factory stock 22RE.

I don't think that 4.30 is gonna sell out from under me. If a decent price on a 4.10 doesn't present itself soonish, it's an option. It's really the limited slip that I want. Drive train dudes already want at least $600 to redo the bearings and then I have an open diff, dumb to not do it all at once but here's a secret - that bill would be higher than what I paid for the entire car.

I hit up the new guy in the for sale forum about a diff. Out of 5 cars I'd expect him to have ONE.
 
#15 ·
Good question.:thumbsup:
Why would anyone want a non-LSD differential in snow country?
You could be late for work,on a Wednesday.

I have been frustrated B-4 for the R.R. tire spinning and getting no where.
Even in the rain ,on an uphill left turn lane.
That's why I tossed the 4.10 open diff. (Shame on me.)
You need the LSD unit to work.

Like so many States,you need A/C in the summer and at least an LSD in the winter,or a 4 WD vehicle.
That's what spoiled my move to upper Nevada.
Way HOT and WAY too cold.
The climate dictates your vehicle choices and chosen mods.
 
#16 ·
These long-lasting mounds of snow are actually rare. I had to ask my mother if she ever remembered this much snow in the valley, to which she said "once...when you were two." That was two years after my car was made.
Yes, we were born the same year.

The AC in my truck still blows icy cold, probably because I never used it haha. AC is dead in the Supra...but it has big ass windows and WILL have an operable moonroof :thumbsup:
 
#17 · (Edited)
You have the most anemic version of the 5M that came out, good for 150 peak hp. The 85 5M had 172 hp due to higher compression, intake manifold, electronic ignition, a potentiometer-style TPS, a knock sensor and a much better ECU system that could fine tune the fuel/ignition curves. Adding a header and bigger exhaust helps the power out a bit, too. I think the 3.73 gears are just too high for that weak of an engine, and would be better suited to a later model or modded engine. The turbo guys LOVE those 3.73s and the rare 3.42s to help build boost quicker, so you have gearsets that you could always sell.

My first supra was an 83 p-type with an automatic. It was a feb. build date so it had the 3.73 gears in it. It was very slow on takeoff and I had to downshift to pass or climb hills, but it got decent gas mileage. I soon added a Pacesetter header and catback exhaust which helped it out a little. It never did have low end grunt though.

Do you want more power, lower gears, or maybe a little of both? No one has mentioned the 3.90 gears that come in the Cressida sedans from 85 to 88. They usually have open diffs, but you could swap in the lsd center section along with the stub shafts from an lsd diff. Yes, there IS a difference in the little stubshafts between LSD vs. open, so keep the stubs with their corresponding center section. It's also good to keep the r&p with it's case, to make shimming the pinion depth easier.

You can bolt on a few parts to make more power, but you can also tune what you have. I'm sure you already know about advancing ignition timing. On our engines, the cams can be advanced/retarded individually in relation to TDC, and you can also change valve overlap. Toyota uses a dowel and a series of holes in each cam and cam gear to allow for machining varience, but racers back in the day used them to fine tune the cams and move the powerband. 82's even got 5 holes in each cam instead of the later cams only having 3. There are threads on the forum or in archives all about this.

The main reason for noise from the rear end is the pinion bearings losing their preload because the crush sleeve crushes more from pinion deflection. Weir makes a solid spacer and shims for us to eliminate that weak link. They also make an lsd gripper kit that replaces the weak parts in the lsd that break or wear and reduce the locked effect. You could also shim the springs tighter, and research the right kind of oil to use in the rear diff to make it perform correctly.

*Horsepower figures quoted from engine specs that I looked up in a Motors repair manual in a public library back in 2002.
 
#19 ·
*Drops knowledge
Thank you.
I didn't even know about a 3.90's existence. I think I've read some Cressidas had LSD too.

I'm not honestly expecting a powerhouse machine from what I have. Look at it like this - a bare bones 22RE in an xtracab, long bed pickup has been my DD since Oct 2004. This "anemic" '82 5mge is a screamer compared to what I'm used to.
 
#21 · (Edited)
Cressidas that had lsd are rare, and was part of a sort of "sport package" that also included a 5 speed manual and motorized adjustable rear shocks that switched from comfort to firm dampening. They could also come with a 4.10 ratio rear diff as previously mentioned, so best to either read the data plate on the firewall or get underneath and count the turns of the driveshaft.

So if I understand this right, you want a lower ratio for your truck than it has now to give it more grunt and still keep the highway rpm's somewhat tame? Is the truck auto or 5 speed? Automatics usually have a higher overdrive gear than manuals, so that and tire size could help determine your ideal ratio.

Since the truck is a 22re, have you read about the Supra AFM upgrade? You can use only the 82 supra AFM and directly swap it over, plug and play, to increase the airflow into the engine. It's the only year that the signal voltage transition matches the 22re afm; all other years are exactly the opposite and won't work. This makes 82 supra parts even harder to find. The igniter is also a one year wonder and is one of the likeliest parts to fail, making it the hardest part to find.

A friend of mine that owned a Toyota junkyard started out with a 1987 Toyota 2wd truck that he used to pull a car trailer hauling cars home from the weekly salvage auctions. He named his truck "stretch" because it was a metallic gray extracab longbox with the 22re and automatic with a column shifter. He worked that truck hard, but still took care of it. He replaced a blown head gasket at 140,000 miles with a Toyota head gasket that never blew again. He upgraded the front brakes to the one ton brakes. He redid the box 3 different times because it would rust through (patched it first, new box sides the second time, replaced with a solid used box the last time). To make a u-turn required careful planning and either a 3 point turn or running over a couple of curbs. He sold it with 450,000 miles on it, and last he knew the guy who bought it had 570,000 miles on it, still on the original engine and tranny. Awesome truck.

I saw a pic in another thread of your truck. You do NOT have a longbox; in fact Toyota never made an xtracab/longbox configuration from 89 - 95. You might have to double-check your axle code because you might have the more common 4.10 gears already!
 
#23 ·
I saw a pic in another thread of your truck. You do NOT have a longbox; in fact Toyota never made an xtracab/longbox configuration from 89 - 95. You might have to double-check your axle code because you might have the more common 4.10 gears already!
Didn't realize they even came longer than mine. It's a 6 footer. And yes, I've been scratching around for an 82 AFM...I have ONE but I need it elsewhere LOL.
I am NOT actually looking for a different ratio for the truck. Just the parts to give it limited slip.
 
#22 ·
lots of canadian mx73 cressidas came factory LSD, hard to find a open diff. both my supras diffs are factory LSD, as is my mx83 cressida. Canadians got that "benefit" with whatever packages they were selling back then.

they're all crap though, unless you re shim them with new clutch discs, but even then, can only do so much..depends what you want from a locking diff
 
#24 · (Edited)
Lexus IS200's, Altezzas or whatever you guys call them have 7.5" open and Torsen diffs in them, and are a lot newer, Casings different obv.
As someone whose had a ma61 LSD apart
> http://driftoy.proboards.com/thread/242/ma61lsd-strip-rebuild

I can tell you that to do it properly it costs a hella lot in parts and bearings and seals to rebuild a Ma61 lsd, and to start with you have to have a really good condition diff, and it's best left to the professionals when setting up the backlash ect, so include labour for that. If i was to do it again, i'd not bother and get a KAZZ diff, as you can't really get away from the fact that the kazz is superior in terms of response and sheer number of clutch packs over the pissy amount in the toyota. Click the link ^ and you'll see whats it looks like all stripped down
 
#25 · (Edited)
Ooh, I bookmarked your build thread already, so excuse me while I investigate your advice :)

edit - hmm, seems KAAZ makes Supra diffs, just not Mark II. Which one are you thinking, Altezza?

edit 2 - dude, thanks for the tip on the Lexus stuff, I am already finding options available for the same $$$ as 34 year old parts...
 
#27 ·
I looks like you need to swap out the attachments or do the entire assembly to me.

NO ONE has discussed this,that I have seen or read,so far.
How is it different and what are the advantages?
I see no top "brace". Maybe the out drives have the same bolt spacing.
IS 200? Really?
How many IS 200's are out there and what years does it include?
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#30 · (Edited)
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