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TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

TR7 to other axle swap?
Posted by: TRip
Date: April 16, 2010 01:03PM

Hello everyone,

Spring is here and I've been eager to get back to working on the 7.

The rear brakes have to be done from drums to cylinders. I also wanted to add a nice set of rims. Thing is rims are very limited for the 3 3/4 bolt circle.

I have researched axle swaps and gone through the archives here. There are a lot of MG, Spitfire etc swaps but haven't seen any 7's.

Basically, I'm looking for a straight forward bolt in swap (if possible) with:

1. LSD
2. disc brakes
3. a more common bolt circle
4. bolts right up and fits under the car w/ no shortening.

And I think the most important question - is it worth even considering?

Or, should I just do the brakes on the present axle?

Trip



Edited 1 time(s). Last edit at 04/16/2010 01:05PM by TRip.


minorv8
Jukka Harkola

(268 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: TR7 to other axle swap?
Posted by: minorv8
Date: April 16, 2010 02:15PM

I don´t think ´that you´ll find a replacement that bolts right up. Volvo 240 series might be one option, the axles are relatively narrow. I have a TR7 axle in my Morris and have fabricated simple brackets to mount rear brake calibers. I have done two sets, one to fit inside 14" rims and another for 15" wheels. I can provide you pics if you are interested.


TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 16, 2010 02:18PM

Hi Jukka

Thanks for the insight. Yes, I'd definitely like to see the pic's that you have.

Thanks

Trip


tr8todd
Todd Kishbach

(390 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: TR7 to other axle swap?
Posted by: tr8todd
Date: April 16, 2010 02:19PM

Most people go to a Ford 8" or 8.8" rear. You will need to either cut one down or compensate with wheels offset if you can find one close enough width wise. Fords either use a 5X4.5 or a 4X4.25? bolt pattern. Most of the Ford ones you see came out of a Mustang or T-bird. They were cut down, and use custom axles. All of the suspension mounts need to be changed as well. All told, your looking at a couple of grand worth of work. If you can find a rear end from another car that carries a 4X100 bolt pattern, you can redrill the front hubs to match that. Anything larger than that is out of the question given the size of the front hubs. The last one I did was a little out of the ordinary. I used an 8.8 out of an Explorer. One side is 3 inches longer than the other bedause of the way the truck is built. I cut down the long side 3 inches and used two of the shorter axles. That gave me something that was close enough to make work with wheel offset. I used redrilled Rover SD1 fronts to get a 5 bolt pattern. Now I have a really stout rear end, Posi, huge disc brakes front and rear, larger wheel bearings, and strong 5 bolt wheels. Given the 5X4.5 pattern, finding wheels was easy. My total cost including the rear ends, wheels, tires, and brakes was around $2500. It was a lot of work, but it solved all of the TR8s weak points in one shot for the least amount of money. I'd do it again. Wheels are 16X8 Enkei RPF1s with 225/45/16 tires. Brakes are Willwood.
DSC01612.jpg


TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 16, 2010 02:27PM

Hello Todd

I hadn't planned on such a huge project dollar or mod wise. Wow, that's far more than I expected!

I was hoping to match the fronts as well but this looks like it would be a pretty daunting project.

Amazing looking TR, by the way! Those wheels really make the car!

Thanks for the info Todd,

Trip


v8ian
ian stewart
just north of London, United Kingdom, Planet Earth
(54 posts)

Registered:
12/24/2009 04:06PM

Main British Car:
67 Ford Cortina 3.9ltr Rover

authors avatar
Re: TR7 to other axle swap?
Posted by: v8ian
Date: April 16, 2010 03:27PM

Whats the width??


Dan B
Dan Blackwood
South Charleston, WV
(1007 posts)

Registered:
11/06/2007 01:55PM

Main British Car:
1966 TR4A, 1980 TR7 Multiport EFI MegaSquirt on the TR4A. Lexus V8 pl

authors avatar
Re: TR7 to other axle swap?
Posted by: Dan B
Date: April 16, 2010 03:28PM

Hey Todd,

How much of that $2500 was spent on the Wilwood brakes? Could Trip use the Ford brakes from the Exp. diff?

Dan B



TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 16, 2010 06:55PM

Hi Dan,

Ya, a straight forward stock Ford brake that comes with the axle is just fine. This isn't my dream car after all... I'm just wondering if a swap is simple enough and not to pricey to do on this particular car - compared to the $$$ for TR 8 drums, cyls, shoe kit etc. and front TR8 rotors calipers, pads.

The TR7 brakes are real sucky as it is and need doing anyway!

This car is my learning car, so hey why not consider it.

PS. I haven't learned to weld yet.

Trip


tr8todd
Todd Kishbach

(390 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: TR7 to other axle swap?
Posted by: tr8todd
Date: April 16, 2010 08:37PM

Willwood calipers run about $130 a piece. They won't bolt on directly to the TR or the Rover struts. You will need to make up intermediate brackets that bolt to the struts(3.25" bolt spacing) and also to the calipers(5.5" bolt spacing for Chevy spec and 3.5" for Ford spec) I went with stock rear solid Explorer rotors in the back and adapted Jeep Cherokee vented rotors on the front. The fact that I have brakes designed to stop 7500 pound SUVs on a 2300 pound TR8 hasn't escaped me. Yes it is overkill. The next time I do something like this, I will not use stock based rotors. I will use Willwood aluminum rotor hats and brake rotors instead. A little more expensive, but lighter and easier to reproduce. Instead of having to bolt the rotors to the hubs, the aluminum hats will sandwich between the wheels and the front hubs. You can do an axle swap for a reasonable price if you can do the fabrication. Mine took about 8 hours of cutting, grinding and welding, and another day to pull two rear ends out of trucks in the junk yard. I still have one rear housing, and posi gear cluster that hasn't been cut down, but I only have the two long axle shafts. I would either have to buy two new short shafts or send these out to be shortened and resplined. A cost of 200-300 dollars.


bsa_m21
Martin Rothman
Vancouver, Canada
(216 posts)

Registered:
01/06/2009 11:41AM

Main British Car:
1980 TR7V8 Rover 3.9L

authors avatar
Re: TR7 to other axle swap?
Posted by: bsa_m21
Date: April 16, 2010 09:00PM

For a nifty rear end, a lot of people also go for a Jag IRS rear end. Check out www.forum.triumphtr7.com. There are quite a number of write ups.

However, the biggest bang for the buck is to just change the front brakes to vented rotors with 4 piston calipers. Replace the stock 5spd rear wheel cylinders with TR7 4 speed cylinders for more brake pressure (these are the same as were on TR8's), but leave the rest alone. Tons of braking power for minimum cost. You can buy a bolt on kit from Woody's for under $800 (http://www.thewedgeshop.com).

M.


TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 19, 2010 08:17PM

Hi Ian,

I'm not sure from where to measure the width. Drum center to drum center or brake back plates?


TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 19, 2010 08:21PM

Martin,

Yes the Jag IRS is nice and I had been considering it before but this present car isn't a clean base to start from so The IRS will be on the next project TR.


v8ian
ian stewart
just north of London, United Kingdom, Planet Earth
(54 posts)

Registered:
12/24/2009 04:06PM

Main British Car:
67 Ford Cortina 3.9ltr Rover

authors avatar
Re: TR7 to other axle swap?
Posted by: v8ian
Date: April 20, 2010 04:45AM

Overall width, IE drum face to drum face


Dan B
Dan Blackwood
South Charleston, WV
(1007 posts)

Registered:
11/06/2007 01:55PM

Main British Car:
1966 TR4A, 1980 TR7 Multiport EFI MegaSquirt on the TR4A. Lexus V8 pl

authors avatar
Re: TR7 to other axle swap?
Posted by: Dan B
Date: April 20, 2010 08:29AM

I think there is a great deal of fabrication required to get a Jag IRS to fit, but it has been done. In fact, if you look on the TR7/8 forum, there is/was a company in Australia that specializes in the Jag IRS for TR7/8. You could also go back on here and look at Jim's posting on the Jag IRS, as he built two conversions for MGB, one in the Roadmaster project and the other in his roadster. (I wonder why MG convertibles are "roadsters" and TR7s are "DHCs.")


v8ian
ian stewart
just north of London, United Kingdom, Planet Earth
(54 posts)

Registered:
12/24/2009 04:06PM

Main British Car:
67 Ford Cortina 3.9ltr Rover

authors avatar
Re: TR7 to other axle swap?
Posted by: v8ian
Date: April 20, 2010 02:58PM

In my Ford. I run a Mid 70s Celica axle, Bigger internally than a 8" other than the ring gear, shafts etc are bigger, measures 56"1/4 face to face, I think its the same bolt pattern as the Triumph, Get the right axle and it come with a LSD, and the axle is UNBREAKABLE [so far] that includes 100s of Drag launches on some super sticky treads



TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 20, 2010 05:50PM

"Overall width, IE drum face to drum face"

Thanks Ian.


TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 20, 2010 05:52PM

Hi Dan

You're right, Jag swap does require a great deal of fabrication and knowledge. Way above my abilities and more than I want to do on this car...


TRip
Trip Anthony

(162 posts)

Registered:
08/18/2009 01:16AM

Main British Car:
1980 TR7 performance 4 cyl

Re: TR7 to other axle swap?
Posted by: TRip
Date: April 20, 2010 05:55PM

Ian, it may be hard to find a mid 70's axle with LS especially up here in Canada. But it does sound like a nice option, though.


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