Allan pics of front Bolsters

Allan the one with the mounting holes sticking down is the 560. As you can see it sticks down about 2.5" lower than the MTA does in relation to the frame rails.

Couldn't get it to take both pictures in one post.

Here is the MTA

I think I got it figured out.

When they went to the larger tires on the rear of a 560, the extra 2.5 inches was added to raise the front of the 560 so the tractor would set level with the back.

What do you guys think?

Gary

I think tires made a bit of difference, however my SM had 6.50x16 and 560 and 656 had 7.50x16, and until I put 16.9x38 tires on rear, both always sat high on front. one could notice it in the yard as well as in the operator's seat. Those 15.5x38 that my 560 and 656 came with, really weren't much higher tire than 13.6x38. That 15.5 is a low profile damn tire.

I think the wide fronts are all the same, can't comment of the narrow, I just don't know. Bear in mind I'm not going by part numbers, just all those many years being around those tractors.

There is no room for the steer arm and the frame rails are even with the bottom of those holes, where on the 560 the rails are 2.5" above the bottom of the mounting holes.

Gary

Something you might check, as it just hit me the reasoning for needing the spacer. All pre 1958 tractors had the steering shaft go to the top of the radiator. On 560 and 656 that same shaft ended at the top of the bolster. I expect that bolster had to be built thicker at the center, to give strength for the punishment a narrow front would give.

My SM was narrow front, however check this one also, I believe my 300 had longer spindles than the 560 or 656. Just wondering if SM, SMTA, 400 and 450 also had longer spindles than 560 and 656. Thicker bolster and shorter spindles may well be the difference. I don't know if I'm right but it makes sence. I do remember looking at 560 when new, and thinking I'm glad I didn't go narrow front with that short steering shaft.

I think tires made a bit of difference, however my SM had 6.50x16 and 560 and 656 had 7.50x16, and until I put 16.9x38 tires on rear, both always sat high on front. one could notice it in the yard as well as in the operator's seat. Those 15.5x38 that my 560 and 656 came with, really weren't much higher tire than 13.6x38. That 15.5 is a low profile damn tire.

I think the wide fronts are all the same, can't comment of the narrow, I just don't know. Bear in mind I'm not going by part numbers, just all those many years being around those tractors.