Author Topic: Solid axle 3rd Member Interchange? (Read 14195 times)

SqWADoosh · « **Reply #30 on:** May 09, 2016, 05:02:09 PM »

Quote from: mudmaster on May 09, 2016, 04:58:56 PM

I was mostly saying it cuz it was used in the front so it was broken in that way.

My understanding is that the gears turn the same way in a standard pinion third whether mounted front axle or rear.

Plainview · « **Reply #31 on:** May 09, 2016, 05:07:00 PM »

Being the worry-wort that I am, I read somewhere while researching this that fronts turn opposite of rears...

I suppose I could go put the front axle up on stands, engage the 4WD and see which way things are turning.

mudmaster · « **Reply #32 on:** May 09, 2016, 05:14:54 PM »

Pretty sure front is reverse rotation. Doesn't matterif it's a HP or not

Plainview · « **Reply #33 on:** May 09, 2016, 05:19:47 PM »

So.... does that mean it'll self-destruct if I drive on it a bunch? I've got a trip coming up at the end of the month that I'm trying to get the truck in shape for...

mudmaster · « **Reply #34 on:** May 09, 2016, 05:24:37 PM »

:)bestgen4runner could say for sure.

:)bestgen4runner · « **Reply #35 on:** May 09, 2016, 05:30:24 PM »

My

If the price is good do it.
Its not going to blow up! That I promise you. worst thing that could happen is some minor noise due to the change in direction of the gears. In my opinion its going to work fine and probably won't make a peep of noise.
I would do it.

SqWADoosh · « **Reply #36 on:** May 09, 2016, 05:48:21 PM »

The only thirds that use reverse cut gears are high pinion. People use low pinion thirds in both axles every day.

mudmaster · « **Reply #37 on:** May 09, 2016, 06:11:28 PM »

Quote from: SqWADoosh on May 09, 2016, 05:48:21 PM

The only thirds that use reverse cut gears are high pinion. People use low pinion thirds in both axles every day.

Correct, but these are standard cut that were broken in on the front (reverse rotation). They will now be used in the rear. If Chris doesn't have any concerns then neither do I.

blackdiamond · « **Reply #38 on:** May 09, 2016, 07:10:53 PM »

A standard third turns the opposite direction in the front (drive side of the gears) than it will when turned around in the front (coast side of the gears). This is why front ring gears break more than rear, they normally run on the weaker side of the gears. A reverse cut/rotation high pinion should, I believe, make the front differential run on the drive/strong side of the gears. The added benefit is the high pinion, but you don't run them in the rear because it would be max load on the weak side of the gears.

The only issue that I could think of from running switching a front to a rear is if the perfect setup for the coast side of the grears doesn't translate to a perfect setup for the drive side of the gears. Likely the noise previously referenced.

Chris - Is the setup procedure from Toyota the same for a front and rear differential or do you shim them differently based on the pattern on the drive or coast side of the teeth?

Plainview · « **Reply #39 on:** May 09, 2016, 09:02:12 PM »

Okay - bestgen has convinced me.

If it blows up on my trip he can split the towing fee with me.

I have AAA premium and will only be 110 mi from home...

:)bestgen4runner · « **Reply #40 on:** May 10, 2016, 07:24:17 AM »

The setup for front and rear diff is the exact same.
Every ring and pinion setup checks the pattern on both sides of the teeth.

Plainview · « **Reply #41 on:** May 10, 2016, 07:46:09 AM »

Well, I can see how it *could* be of concern. Correct me if my logic is wrong here... I've never rebuilt a diff myself but I understand what's involved.

When you set up a diff it's not under load. You check the pattern to make sure the gear teeth are engaging properly but when you put it into service things are going to shift just a little bit due to the much greater forces involved. There is clearance and play under load that can't be duplicated on a bench. So, the teeth start to wear together in a certain pattern on the driven side, and in a different pattern on the coast side because the forces being applied are coming from opposite directions. Now you change the direction in which force is applied and the coast side becomes the driven side, and vise-versa. Because of that little bit of clearance, and because of flexing and play that simply cannot be eliminated, and any wear that has occurred, the teeth will be wearing against each other in a slightly different way than they did before, contacting each other at a slightly different spot, and the loads have changed direction.

I can see how this *could* lead to accelerated wear and noise. Will it? I dunno, guess I'm about to find out.

In the meantime I'd like to get started rebuilding the broken diff - where's the best place to acquire gears and rebuild parts?

redneckcustoms13 · « **Reply #42 on:** May 10, 2016, 07:52:32 AM »

I recently built the dana 80 in my tow rig. Believe it or not summit racing was the best price on everything. I'm running g2 gears and cannot complain a bit about them.

Plainview · « **Reply #43 on:** May 10, 2016, 01:05:00 PM »

Well, if the idiot on CL who's trying to part out his '88 V6 would ever get a clue, I might be able to tell you. He re-posted his ad today, again with no contact info. What a rube.

I'd buy his V6 3rd to rebuild since they're stronger and I'm planning to go V6 at some point in the not too distant future. His truck also has a nice, clean interior that I'd like to have and if it has AC I'd take all those parts too.

:)bestgen4runner · « **Reply #44 on:** May 10, 2016, 01:14:47 PM »

Post your own ad next to his.
Use almost the same wording.
say "hey moron I want to buy your s--t " "post your b-m contact info"
It worked for me once before on a snowmobile hood.
The guy was like "man no wonder I never got any calls"

:)bestgen4runner · « **Reply #45 on:** May 13, 2016, 07:22:27 AM »

Any updates yet?

mudmaster · « **Reply #46 on:** May 13, 2016, 09:08:11 AM »

He picked up the one I had on Tuesday. I think the plan was to install this weekend??

Plainview · « **Reply #47 on:** May 14, 2016, 12:30:33 AM »

mudmaster is da man! Thanks, I really appreciate it!

I should have checked out your rig a little closer while I was there, I'd like to see more of what you're doing with that 4.3.

The third is installed. Cleaning all the little chips and pieces out of the housing was a PITA. Still need to fill the axle with oil, bleed the brakes, and reinstall the driveshaft. I'm on that tomorrow morning, then I'll drive it to work next week to make sure nothing else pops up to bite me in the ass.

:)bestgen4runner · « **Reply #48 on:** May 14, 2016, 07:41:15 AM »

That's great news.
keep us updated on if it makes any noise at all.

Plainview · « **Reply #49 on:** May 14, 2016, 02:06:18 PM »

Well dammit, nothing goes easy...

mudmaster - what year truck did that third come from? The bolt holes in the flange are too small. I didn't even think to check before installing it.

I kind of doubt I can drill them oversize with a hand drill and keep them on-center... Can the flanges be swapped? Does that big nut on the pinion hold the pinion in place?

I was really hoping to be done with this today...

:)bestgen4runner · « **Reply #50 on:** May 14, 2016, 02:53:30 PM »

Not sure how your set for tools but, just swap the flange with your original broken 3rd members flange.

Plainview · « **Reply #51 on:** May 14, 2016, 02:55:08 PM »

And that comes back to my question about the big nut on the end of the pinion. Doesn't that nut hold the pinion in place and/or have something to do with the pinion depth? How do I ensure the pinion is right back where it needs to be when I put it back on?

When you ask how I'm set for tools, what specifically are you referring to? I have whatever sockets, wrenches, torque wrenches, etc. I've needed for most things...?

:)bestgen4runner · « **Reply #52 on:** May 14, 2016, 03:12:39 PM »

Nothing is going to fall apart buy removing the pinion nut. LOL
Your only concern is that you check the pinion preload before and after you swap the flange over.
Many experience techs do this buy feel. If your not sure you will need a inch pound torque wrench to measure effort to turn pinion.
Normally this is done with the 3rd removed from vehicle to get an accurate measurement. (not turning axles)
If the axles are still removed you could do it in the car.
I'm hear if you have more questions.

Plainview · « **Reply #53 on:** May 14, 2016, 06:45:27 PM »

Well, file this whole debacle under "Things That Take Way Longer Than They Should."

bestgen - I wasn't worried about it falling apart but was worried about being able to put it back together properly since you confirmed that the pinion nut does have to be set just right to get the right pre-load on the gears.

Since I don't have an in-lb torque wrench, have never set up a differential before and it was all installed and ready to go I decided to try a different tactic.

I discovered that not only were the existing holes too small, but the pattern was different and only two holes at a time would line up so I bought a 25/64 drill bit which is just a half-a-hair larger than the 10mm bolts, rotated the yoke 90 degrees and using it as a guide I drilled 4 new holes in that flange.

I wasn't sure I'd be able to do a good job of drilling nice, straight holes laying on my side under the truck with a hand drill but it didn't go too bad and the bolts fit nice and snug in their new holes.

After that I filled it with oil and took it for a spin around the block. The new transmission doesn't shift as easily into 1st gear as the old one but otherwise feels okay and there are no strange noises, at least at speeds up to 30 MPH on flat roads.

I just want to throw out a HUGE Thank You! to the folks who've offered help and encouragement on this forum. I really appreciate it, and this is definitely the best 'yota forum out there for dealing with friendly, helpful folks.

mudmaster - if you could let me know what year that diff came out of just so we can make a note of the difference in flange pattern & bolt sizes for the different years that would be cool. And, thanks again for hooking me up!

Only one weird thing is happening right now - I'm not getting the 4WD indicator light on my dash any more. I swapped the sensor from the old t-case into the new one but the light's not coming on for some reason. I'll have to check my reverse lights to see if they're working or not, too.

mudmaster · « **Reply #54 on:** May 16, 2016, 05:38:20 AM »

I'm not sure of the exact year, but from your description I'd say a first gen (79-83). I've done the exact same thing as you to make it work.

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