TR4/4A Wheel fitment on TR4a solid axle vs IRS

[richie]

Hi all,

I currently have 72 spoke 15x6 Dayton's (intended for TR6/250) on my 65 solid axle 4a with 195/75-15 tires. They fit just fine albeit quite aggressive looking with its tire width.

In hopes of replacing the tires with something besides an average all season tire, After much research in tire selection amongst 15" setups (195/65 and 205/60) for 6" panasports, I have been a little disappointed to find no dedicated Z rated summer tire option for the TR. The only exception being non DOT approved Hoosiers which I would never consider for street use.

This has led me to looking into 16" options for the 4a as the 205/55-16 has superior tire selection.

In much research I have found plenty of TR6's running 16x7 Konigs and panasports, all with a +06 to +04 offset, including a TR250. I haven't seem to have found any TR4 or TR4a running this size and often I read about different clearance issues, however I'm not too sure why these would fit a TR250 but not the 4a?

I was wondering if anyone who had more of an idea between the differences in the rear (and front?) measurements between the two cars could shed some light on whether or not the 16x7 would work or not. The way I see it, adding 1/2" on both sides of the rim does not seem that unthinkable the way the current wheels sit. The other question mark is if I would be also minimizing the gap between the hub and wheel when omitting the wire wheel hub extension?

I've attached a photo of the current setup and of a car which I believe is running 16x7 however remains a guess. That car is my inspiration.

Thanks!

 

[TR4nut]

Hi Richie-

Don't have an answer to your question unfortunately, but just in case this hasn't been covered before I wanted to alert you to some potential work if you convert to alloy wheels. If your wheel studs have been cut down for wire wheels, then with a solid axle 4A you will be dealing with some effort to put in longer studs for the alloys - the studs on the 3,4, and 4A are threaded on the back hubs so swapping them out is not an easy task.

Randy

 

[glemon]

I have 15 x 7" Konigs with 205/65s on my TR250. I get no tire rubbing front or rear, the wheels do rub against the front suspension at full lock, I have done some grinding and eliminated almost all of that problem. If you went to 16" wheels you would not have the suspension rubbing problem at all I don't think. Front suspension and body are the same on the 4a, of course the only difference is the rear suspension, can't say for sure, but would not think the solid axle, which has pretty limited travel, would have any problems when the IRS doesn't have had no interference issues at all at the rear. Greg

 

[3798j]

Don't shoot me if I'm wrong, but my belief is the concern or problem with the rear suspension won't be with travel, it'll be getting the correct wheel backspacing so that the tire doesn't come in contact with the leaf springs.

 

[richie]

Good points. Do you have some photos that show the fitment of the 7" rims on your 250? Also what offset are your rims?

Thanks!

 

[PeterK]

Don't shoot me if I'm wrong, but my belief is the concern or problem with the rear suspension won't be with travel, it'll be getting the correct wheel backspacing so that the tire doesn't come in contact with the leaf springs.

I'll agree. We run KN 15x6 with 205/60x15 on all fours. At the rear we have a slight rub between the tire sidewall and the leaf springs. It only happens when the tail is out but I run 1/8" rear spacers on the rear.

I also have a 4A solid axle project that appears to suffer the same as the 3A, so same solution. In the front, there is a slight interference at full lock. It is between the outer rim lip and the rear upper contraol arm. Fixed by grinding off the point off the control arm, maybe 1/4" ground off.

So backspace is just as important. No fender rubbing on either TR.

 

[glemon]

The Konig Rewinds have a 0 offset, I don't know if I have any good pics showing clearance, didn't think about the leaf springs, good point.