Spare wheel tray MK IV

Storing or removing the spare wheel on my ‘48 MK IV is a challenge to say the least. I added 3/4’ spacers to extend the rear bumper so as to slightly reduce the angle of the wheel removal, plus reduced the psi in the tyre, but still remains a struggle. The steel cross-member under the tray is slightly arched approx 1/2" to 3/4" upwards, probably from someone attempting to jack up the car way back when…Attempting to correct would require removal of the tray and other ancillaries. Some early SS showed the rear bumper capable of hinging down to allow access to the spare. As anyone come across this problem and found a creative solution, besides storing the spare on the back seat ?

Hi Daniel,

The problem is actual worse in the SS even with the hinge down bumper. The spare wheel compartment is just not deep enough and I think the SS one is shallower than the MkIV. I just store my spare with minimal pressure and carry a foot pump.


My '38 SS has the swing down bumper design. The rear of the chassis had been partially repaired by a previous owner, but poorly, and I removed that main spring support cross member to repair it, and wrote it up on this forum. It was a lot of work, and it is still not right. The spare tire door does not close all the way, sits on the tire. I think it is either that cross member is still too high, or the body is sagging due to the missing rearmost body mounts. So that will be another task when it comes time to remove the body for a proper restoration.

Hi Rob & Peter,
How is the bumper hinged to allow swing down on the SS. The '48 MK IV has two bolts going thru the chassis ends holding each bumper brackets. I thought of removing the rear bolt on each brackets and replacing them with heavy clevis pins. That would allow a swing down. Lowering the tire psi just about allows the spare tire door to close flush to the body. The engineers at Brown Lane in Coventry had a sense of humor when designing the spare tire tray. Its perfect for a worn-out spare.


Here is what the manual shows. Looks like the bumper is on springs and pulls out before swinging down. This drawing must be the initial idea.

But mine from Jan '38 is not like this.
Clevis pins sounds like a little better than the wing nuts and tapered slots on mine.

There is a story I read somewhere that Lyons took one of these cars on his vacation in France, and he had a flat tire, and he had so much trouble with that swing down bumper that when he got back to the office the first thing he said was he ordered Heynes to change it.
So that’s why only the 1938-39s have it.
But other Mark IV owners have not had great difficulty with it.
A body shop could straighten your rear cross member without removing it.

Rob, Thank you for the illustration and photos. Its clarified the mystery of the swing-down mechanism for me. Before I attempt replacing the rear bolts with clevis pins, I’ll check with a body shop for the capability of straightening the arch on the heavy cross member, without removing the tray. Early side mounts had their advantage by comparison.

I have trouble sliding the tyre out. The hub always scrapes on the underside of the door and a lot of grunting is needed. I think that the body should be packed up another 1/2" (10 - 15 mm). If anyone is doing a body-off restoration, it would be worthwhile thinking of this method. It is hard to imagine that they would have been made with this interference when new, so why is it a problem today? Is the tyre width wider today than it was for the same size of yesteryear?

Hi Peter, I suspect your last sentence gives the reason.