mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Toyota IRS option
Another option for TR4/TR6 and Spitfire/GT6 or any custom IRS for that matter(or my DeDion). 7.5" ring gear puts it inbetween Nissan (Datsun) R180 and R200. The IFS diff in 85-95 Toyota 4X4 pickup and Fourrunner. It has one short stub axle and one longer one. Simply mill the side with longer stub 6mm and use same seal as short stub side. Plug in another short stub and you have a compact narrow,strong IRS unit. I don't know if the 6 bolt pattern is the same as Nissan R200 and R230. You could use the same type adapter to VW type 2 or Porsche 930 CV. Very common and cheap in junkyards. 79-95 2WD rear 7.5" straight axles had ratios of 3.15 and 3.36(rare) 3.42 and 3.58 (more common) 3.73,3.91 and 4.10(most common). Tru-trac Torsen type or 4X4 lockers are availabe for this dif. Here are the pics:
Edited 5 time(s). Last edit at 04/01/2011 08:38PM by mgb260. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
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mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
Actually the Toyota 4X4 front CV axles are short,you would have to modify the end that goes through the hub(shorten and respline?). Also, ADD(Automatic Driveshaft Disconnect) axles use a smaller diameter stub shaft with roller bearings.they can be identified by the pneumatic control box on long side housing. You can change the bearings and seals and use the Non-ADD stubs.
Edited 5 time(s). Last edit at 04/04/2011 03:56AM by mgb260. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
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mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
The 6 bolts in the drive flanges are pressed in and should be removed by pressing out with a socket in a vice. Replace with bolts and nuts to make CV axle changes easy. Also the rear 2wd carriers use larger bearings in V6 vs 4 cylinder models. Front IFS housing may or may not. Most aftermarket lockers and Tru Trac use the larger bearing size. OD is the same, ID is 45mm for small,50mm for large. Simple swap. This diff is the same as 82-86 Supra which had finned cover and different mounting.
Edited 5 time(s). Last edit at 04/05/2011 06:38PM by mgb260. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
Thanks Curtis! There is now another choice for IRS! These diffs can be found anywhere cheap. Plus who would have thought the IFS front diff gears and parts were identical to the rear 2WD axle. Lots of front diffs are reverse cut ring gears and if used in the rear would be weaker because the load would be on the coast side of the ring gear. Toyota must have figured it was strong enough for the front without the reverse cut gears. What amazed me was that the straight 2WD rear axle is a drop out like the MGB Banjo and Ford 8" and 9" and the gears and parts are identical to the front IRS with a cover. Here is a picture of the Supra finned cover all polished up like chrome. I'm thinking of making a sand cast hot rod cover similar without the extra holes but with rear mount. The rear mount is similar to what Ford does on their diffs.
Edited 2 time(s). Last edit at 04/03/2011 05:58PM by mgb260. |
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mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
Link to putting a 82-86 Mark 2 Supra clutch type posi in this diff: [www.4x4wire.com] Also a link on installing a locker. You can also see why you have to replace the ADD stub. [www.toyotasurf.asn.au]
Edited 2 time(s). Last edit at 04/03/2011 09:35PM by mgb260. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
88-2000 2WD pickup 7.5" rear end manual trans 3.42 ratio,auto 3.58 ratios. The IFS is found in 86-95 4X4 Fourrunners,pickups and 93-98 T100 pickups. Most IFS are 4.10 or 4.30. About 6 of them on EBay for $50-200. Then do some junkyard shopping for the 2WD 7.5" drop out rear truck ratios.
Edited 2 time(s). Last edit at 04/14/2011 06:58PM by mgb260. |
roverman Art Gertz Winchester, CA. (3188 posts) Registered: 04/24/2009 11:02AM Main British Car: 74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L |
Re: Toyota IRS option
Jim...are you eluding to an all wheel drive British sports car ? Say like "Roadmaster Unlimited " ?? crafty !
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mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
Art, No. Don't give me any ideas!LOL. Just an alternative to the Nissan and Subaru units already being used in Spitfire/GT6 and TR4/TR6. I did think about using two long stubs and making a Pro Street ,tubbed Bugeye Sprite with the widest tires I could find. I'm surprised you didn't think of that! Imagine with a Rover V8 and Blower sticking out the hood!
Edited 1 time(s). Last edit at 04/06/2011 04:23PM by mgb260. |
Richard/SIA Richard Brengman No. Nevada (401 posts) Registered: 01/17/2014 07:47PM Main British Car: 1969 Triumph GT6+ 225" Buick V6 |
Re: Toyota IRS option
Took a while to relocate this thread.
Do we have a way to "Subscribe"? That long/short setup may prove useful for another project, shaft drive motorcycle engine in place of a VW Bug rear engine and transaxle. Still rear engine and I need a way to center it for weight distribution. No relation to a British car but still fun if I can get it built. |
Richard/SIA Richard Brengman No. Nevada (401 posts) Registered: 01/17/2014 07:47PM Main British Car: 1969 Triumph GT6+ 225" Buick V6 |
Re: Toyota IRS option
OK, picked up two of these today.
Holiday half-price sale at P&P Now find myself with questions. First off, short side axle wobble!? Does anyone know the fix? When converting to a narrow center section as detailed by the OP do both sides then become liable to the stub axle wobble? Seems it would be hard on seals and spider gears? I nearly left the first unit I pulled at the salvage yard due to the short side wobble. Second unit I pulled also has the wobble but not as much This issue shows up on Toyots forums but there does not seem to be a solid answer available. Second, both of the units I got have the ADD. From what I can see this will not matter if I am doing the narrow diff conversion, correct? Seems I may want to get a third one of these WITHOUT the ADD. My projects require a narrowed version for front engine cars with IRS and a full width version for the rear mounted FJR1300 motorcycle engine Tatum project which will also be IRS. For the Tatum I will not want to modify the unit but will want to avoid the ADD. I should have reviewed this thread to remind myself that there are two versions before going to the yard. I suppose I could rig a way to just lock the axle collar in place, or run it with a switch to allow free-wheeling on demand, or a hidden neutral ant-theft device. But for simplicity and lighter weight, does anyone have a log side without ADD that they no longer need? |
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mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
Richard, First I've heard of short side wobble. Makes sense though with high miles on 4WD. The ADD side has more support and uses a needle bearing. You could bore out the housing on the short side to fit the needle bearing. Or replace both sides with bronze Oilite bearings. I would coat either with moly(CV) grease.
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Richard/SIA Richard Brengman No. Nevada (401 posts) Registered: 01/17/2014 07:47PM Main British Car: 1969 Triumph GT6+ 225" Buick V6 |
Re: Toyota IRS option
If I am reading various threads correctly the ADD versions have needle bearings for the stub axles, which would be good as the bearing should be replaceable.
That should fix the wobble. The possibly bad is that the axle does not use an inner bearing race, so a worn axle would have to be replaced. I suspect the new axles cost more than a complete used diff. I just bought a non-ADD long side axle tube on feeBay so I will be getting deeper into this soon. BTW, unless I am looking at it wrong the R&P is revers cut. Which is excellent for my rear engine project. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
Nope, not reverse cut. Newer clamshell type are reverse cut.That is why the 2WD pickup rear axle gears will interchange. I looked up the axle wobble issue. There is no support on the short side after the diff bearing. You would have to bore the diff for the needle bearing on that side. I wonder if there is a speedy sleeve to give a new surface on the axle shaft. There is a steel backed bronze bushing to replace the newer clamshell 7.5 needle bearing. Fits 86-04 but is $60 each.
[eastcoastgearsupply.com] Here is a pic of the bushing on a later stub axle: Edited 3 time(s). Last edit at 03/02/2017 12:26PM by mgb260. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
This guys " Zuk's Gear Install" page has all kinds of info on setting up Toyota ring and pinions:
[www.gearinstalls.com] Click on house on bottom of page for menu to other gear installs. Edited 1 time(s). Last edit at 03/04/2017 08:34PM by mgb260. |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Toyota IRS option
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