Author Topic: Bigger diff in Toyota 8" axle housing? (Read 14530 times)

Hawk Thor · « **on:** Feb 13, 2009, 06:59:21 PM »

I heard the other day that 8" Toy axle shafts fit in Cruiser diffs or some American diffs bigger than the 8" toy diff.

I´m not talking about the HP 8" diff, but diffs from 60 Cruisers.

Has anyone heard this before? Have you seen it done? What has been used for a convertion like this?

joey0712 · « **Reply #1 on:** Feb 13, 2009, 07:14:12 PM »

u can get a diamond housing with Tundra thirds and Cruiser outters.... Its pretty much the baller Toyota axle

dniel · « **Reply #2 on:** Feb 13, 2009, 10:20:09 PM »

A tundra diff could be put in a mini housing. The depth from the mounting flange to were the axles go into the diff is the same on the mini and the tundra-tacoma. It would be a matter of filling, drilling, and tapping the new bolt pattern. You would also have to push out the back of the housing to make room for the braces. A diamond would be easier but if you had time you could do it much cheaper.

THK Matt · « **Reply #3 on:** Feb 14, 2009, 12:22:53 AM »

Quote from: dniel on Feb 13, 2009, 10:20:09 PM

A tundra diff could be put in a mini housing. The depth from the mounting flange to were the axles go into the diff is the same on the mini and the tundra-tacoma. It would be a matter of filling, drilling, and tapping the new bolt pattern. You would also have to push out the back of the housing to make room for the braces. A diamond would be easier but if you had time you could do it much cheaper.

we talkin the 10.5in tundra diff?

i'd like to see this.

Hawk Thor · « **Reply #4 on:** Feb 14, 2009, 07:12:02 AM »

Cutting the "diff cover" off should be easy. Then you would just have to make a new cover for the back/front of the housing to fit around the ringgear and have good oil capacity.

Does anyone know if normal shafts would fit, or are the Tundra shafts larger? Would one need narrowed Tundra shafts or custom made shafts or is there an OEM shaft that might fit?

DTB · « **Reply #5 on:** Feb 14, 2009, 07:19:17 AM »

Seems to me there would still be serious clearance issues on the top and bottom of the ring gear and the housing (top and bottom)

I mean you are really talking about building a custom axle not just modifying a 8".....it sounds like a lot of work!

Hawk Thor · « **Reply #6 on:** Feb 14, 2009, 08:54:15 AM »

It might be worth a shot for someone that feels capable of doing the mods. It would be alot cheaper then a diamond axle and in a few years wrecked Tundras will be plentiful. I belive that when someone has taken the leap then others will follow.

The first guy that shaved his housing must have been trying out an idea, making it almost as flat as a custom axle, right?

dniel · « **Reply #7 on:** Feb 14, 2009, 10:15:24 AM »

Sorry to get everyone excited but I'm talking about the older tundra-tacoma diff that people refer to as the 8.4". I think this is a much stronger 3rd than the mini 8". It has a larger pinion, main bearings, and ring gear bolts. The best thing is the two trusses that go between the main caps. These make the 3rd more rigid and prevent ring gear defflection which is what kills most 8" 3rds.

The bolt pattern for the housing is different and the bolts are bigger so this would have to be changed on the mini housing. The trusses take up space so the back of the housing would have to be enlarged. These diffs are strong enough that I think the axle shafts would be the weak point instead of the expensive 3rd member.

H8PVMNT · « **Reply #8 on:** Feb 14, 2009, 10:36:49 AM »

Check out the trusses.... cool! I think it would be a pretty good idea. Would the trusses fit on a regular 8" third? Then you could just add them and make a new diff cover area...

dniel · « **Reply #9 on:** Feb 14, 2009, 11:16:35 AM »

Probably not but I have never checked. It would be better to run the whole third for the bigger pinion as this is the next weak point after you stop the deflection. Its been awhile but if I remember right the tundra-tacoma pinion is 30 spline and the 8" is 27 spline. The 8.4" pinion is also thicker.

THK Matt · « **Reply #10 on:** Feb 14, 2009, 11:32:40 AM »

I think it'd be easier to take a 8.4 rear housing and cut the tubes off and weld on the mini tube ends... then you would need to redrill, make the fron of the housing bigger.... blah blah blah.

dniel · « **Reply #11 on:** Feb 14, 2009, 12:17:24 PM »

Quote from: thatHOkid on Feb 14, 2009, 11:32:40 AM

I think it'd be easier to take a 8.4 rear housing and cut the tubes off and weld on the mini tube ends... then you would need to redrill, make the fron of the housing bigger.... blah blah blah.

Yes for the rear this would be much better the info I posted is mainly for the front. I think the taco rear is 60.5" so you could run it as is without to much width difference.

bhigdon101 · « **Reply #12 on:** Feb 14, 2009, 03:12:53 PM »

Quote from: dniel on Feb 14, 2009, 10:15:24 AM

Sorry to get everyone excited but I'm talking about the older tundra-tacoma diff that people refer to as the 8.4". I think this is a much stronger 3rd than the mini 8". It has a larger pinion, main bearings, and ring gear bolts. The best thing is the two trusses that go between the main caps. These make the 3rd more rigid and prevent ring gear defflection which is what kills most 8" 3rds.

The bolt pattern for the housing is different and the bolts are bigger so this would have to be changed on the mini housing. The trusses take up space so the back of the housing would have to be enlarged. These diffs are strong enough that I think the axle shafts would be the weak point instead of the expensive 3rd member.

like what year?
and what gears are available for the 8.4
and what locker?

brian higdon...

OOPS · « **Reply #13 on:** Feb 14, 2009, 04:33:40 PM »

like what year? All 2wd and 4wd T100's, '00-06 Tundra's, and ?? Sequoia's use a newer/stronger 8" 2-pinion diff. Tacoma 4x4's and Tacoma PreRunner's that don't come with the electric locker (aka "non-TRD), as well as V6 Tacoma 4x2's also came with this diff.

what gears are available for the 8.4 4:11,4:56,4:88, 5:29

what locker? ARB, Detroit, Lockrite

The 08-09 Tundra rearend is even beefer.

Here is a lot of good Toyota diff info

http://home.4x4wire.com/erik/diffs/

dniel · « **Reply #14 on:** Feb 14, 2009, 05:17:46 PM »

The cheapest would be to get it from a taco as these are the most common. People always want more for the tundra just because it's a tundra even thuogh its the same. There is a guy on my local craigs list selling a tacoma diff with a factory limited slip for 275$. It has been on there forever and I have been thinking of calling him an offering him 200$ even though I have no use for it. It would be perfect for a front axle running stock birfs.

THK Matt · « **Reply #15 on:** Feb 14, 2009, 08:48:21 PM »

Quote from: dniel on Feb 14, 2009, 12:17:24 PM

Yes for the rear this would be much better the info I posted is mainly for the front. I think the taco rear is 60.5" so you could run it as is without to much width difference.

I was not meaning to use it as a rear axle.
I was meaning cutting the ends off a mini front axle and welding them onto the taco rear end... and making the tubes the correct length to match a 85 housing.

dniel · « **Reply #16 on:** Feb 14, 2009, 10:40:59 PM »

Quote from: thatHOkid on Feb 14, 2009, 08:48:21 PM

I was not meaning to use it as a rear axle.
I was meaning cutting the ends off a mini front axle and welding them onto the taco rear end... and making the tubes the correct length to match a 85 housing.

This could be done but I think might be more difficult than you think. If you are thinking to use the ends like were you cut and turn the knuckles this requires a very precise inside diameter to press in to. If you mean cutting farther up and splicing the housings together this would depend if the OD on the housings is the same.

Pat over on pirate has a great write up on how to widen a mini truck housing using a thick piece of dom. The way he did it could be applied to shortening as well. He used dom with the correct inside diameter and milled the outside with a lathe to press into the housing. You would also need an axle jig to make sure everything was true.

This could all be done if you have the tools and skill but is far beyond my abilities. Drilling and tapping holes may be a pain but it's something I know I can get right.

Maybe Oops could put a link to Pat's axle build thread. Sorry I'm e-tarded.

OOPS · « **Reply #17 on:** Feb 15, 2009, 06:50:52 AM »

Quote from: dniel on Feb 14, 2009, 10:40:59 PM

Maybe Oops could put a link to Pat's axle build thread. Sorry I'm e-tarded.

I will see if I can find it.

OOPS · « **Reply #18 on:** Feb 15, 2009, 09:56:28 AM »

Here it is.

http://www.pirate4x4.com/forum/showthread.php?t=654231&highlight=

dniel · « **Reply #19 on:** Feb 15, 2009, 11:38:29 AM »

Quote from: OOPS on Feb 15, 2009, 09:56:28 AM

Here it is.

http://www.pirate4x4.com/forum/showthread.php?t=654231&highlight=

Hawk Thor · « **Reply #20 on:** Feb 16, 2009, 04:53:32 AM »

Does anyone know if there are any diffs that the axle shafts fit into? Ford 9", Cruiser 9,5", Dana 60 diff or something. I have seen alot of guys running chromoly, marfields and Longfields, cromoly and Long shafts making the 8" diff the weak point.

If there was a way to fit a bigger diff by simply clearancing the "cover" on the housing and drilling and tapping new stud holes and then stuffing the diff in there I think alot of people would do it. Not many people have access to a huge ass lathe or can justify the cost and hassle of an axle jig for one axle build. If one might be able to piece this together with OEM stuff found in wrecking yards, backyards and barns then many would try and we would soon find the best combination.

So does anyone have a big diff laying around and a spare axleshaft? That might be the first step, if something fits then we might be able to forego the custom shafts for something OEM Toy, Ford $That\'s Gay$ , GM, Nissan or other.

THK Matt · « **Reply #21 on:** Feb 16, 2009, 06:40:01 AM »

I don't think so.

Hawk Thor · « **Reply #22 on:** Feb 16, 2009, 08:06:10 AM »

I was just researching this a little and I found a comment from the Marlin Crawler dealer in Iceland, Halli at K2 motorsport. Someone was asking him what they could do about the the front diff in his 80 series Cruiser on 44" tires.

He said that some people have opted to put Dana 44-60 diffs in the axles, one mountain rescue team close to me is trying this in their 80 on 38" tires and its working well. He also said that a high pinion, reverse 9" Ford diffs should be plenty.

So I ask again, does anyone know the splines and axle diameter in a Toy and a 44-60 or a Ford 9".

I will be asking Halli about this when I get a chance. I´ll also get in touch with the rescue team. I´ll let you know what I find out.

dniel · « **Reply #23 on:** Feb 16, 2009, 10:25:47 AM »

Quote from: Hawk Thor on Feb 16, 2009, 04:53:32 AM

Does anyone know if there are any diffs that the axle shafts fit into? Ford 9", Cruiser 9,5", Dana 60 diff or something. I have seen alot of guys running chromoly, marfields and Longfields, cromoly and Long shafts making the 8" diff the weak point.

If there was a way to fit a bigger diff by simply clearancing the "cover" on the housing and drilling and tapping new stud holes and then stuffing the diff in there I think alot of people would do it. Not many people have access to a huge ass lathe or can justify the cost and hassle of an axle jig for one axle build. If one might be able to piece this together with OEM stuff found in wrecking yards, backyards and barns then many would try and we would soon find the best combination.

So does anyone have a big diff laying around and a spare axleshaft? That might be the first step, if something fits then we might be able to forego the custom shafts for something OEM Toy, Ford $That\'s Gay$ , GM, Nissan or other.

Many people have begun using the tacoma diffs in there diamond axles. I think it is comparable in strength to a cruiser 9.5". The conversion I'm talking about is not common because it is a hassel. I don't mean to make it sound to easy. It would take a long time it's just that it can be accomplished by someone with moderate skills.

The cruiser 9.5" takes the same 30 spline shaft that a 8" and 8.4" do. The fj60 front axle has a 9.5" diff. If I remember right it is 58.5" the same as an ifs rear. The outers are the same as a mini truck and will accept 30 spline longs. They also come with the vented rotors everyone swaps onto there trucks. I have seen a few mini truck sas done with this axle and I'm not sure why it is not more popular.

The same 9.5" comes in the fj80 and some come with E-lockers. Some guys over on Ih8mud.com have swapped this e-locker into their fj60 axles. It seemed to be about the same amount of work it takes to put a regular e-locker in a mini housing. Were the axles go into the diff one side needs longer splines for the locker. If you are getting longs anyway bobby knows the right spline length.

fj60 axle with fj80 e-locker. Not sure if this is front or rear they are both offset.

Longer spline needed for locker.

THK Matt · « **Reply #24 on:** Feb 16, 2009, 11:21:05 AM »

looks like a rear.... I see where the rear bumper is bolted the end of what looks to be the frame....... isnt that a gas tank skid?

dniel · « **Reply #25 on:** Feb 16, 2009, 05:03:37 PM »

FJ60 front. You can tell how much bigger the third is. Outers are the same as a truck-4runner. With some minor modification this will take the fj80 e-locker that I posted above. I'm trying to get back to original posters question. This is basicly a mini truck housing with a cruiser 9.5" diff. The only real difference is it will match an ifs rear without spacers.

It would also match up well with the tacoma rear if you put the standard 1.5" spacers on the fj60 axle.This would give you the stronger diffs your looking for front and back and also a little wider stance without modifying anything. Around here the front fj60 axles usually sell for less than the front mini truck axles. The tacoma axles are also fairly cheap if you get the non e-locker which are the strong ones with the trusses. If you are looking for strength stay away from the tacoma e-locker as this is the same as the older V6 diffs strength wise. $Beer Chug\'n$

Joey88RUNR · « **Reply #26 on:** Feb 16, 2009, 05:44:27 PM »

You say "stay away from the tacoma e-locker as this is the same as the older V6 diffs strength wise".......i thought they were the 8.4" R&p that was stonger

dniel · « **Reply #27 on:** Feb 16, 2009, 07:27:30 PM »

V6

E-locker

They even use the same gear sets. The one with the trusses is the tacoma without the e-locker. As far as I know the only factory traction device for the 8.4" is a limited slip. The one with the trusses is actually also an 8" ring gear but uses a different gear set than the earlier diffs. Many people call it a 8.4" to make identification easier.

Hawk Thor · « **Reply #28 on:** Feb 17, 2009, 07:34:15 AM »

I found out that if you swap the center out for a GM 12 bolt center then you can re-use the Toy shafts.

I guess that I will just end up going to complete Nissan Patrol housings when I start breaking excessive toyota axle stuff.

Redbeard1 · « **Reply #29 on:** Feb 18, 2009, 09:52:41 PM »

Patol axles like these?

Hawk Thor [OP]

Hawk Thor [OP]

Hawk Thor [OP]

Hawk Thor [OP]

Hawk Thor [OP]

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