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I keep hearing about bumpstop. Not sure what it is for sure except maybe if you hit a bump the oil pan hits the drag link??? I have my front end off and I am fixing to remove some leafs from the springs. Every one says you can get 3” drop with no issues??? I have 6.5 inches from
Tire to fender, but the steering bar that runs from hub to hub by the axle is only 3 3/4 inches below the oil pan. No way will 3/4” be enough room.....Help!!!!

Beneath your oil pan is the tie rod not the drag link. What engine does your truck have and how many leafs do you have now? You are far better off to have your stock dropped axle dropped further than removing leaf springs.

- EM

Welcome to the site!

The term is actually bump steer and it is associated with changing your
steering geometry from factory specifications to "something else". As your
vehicle enters a suspension stroke, there is a tendency for the wheels to
want to steer themselves. This can range from a "jolt" in the steering wheel
during a suspension stroke to something more violent that can jerk the
wheel from your grip. It potentially puts you, any passengers and any other motorists
or pedestrians in your vicinity in danger. I'd suggest doing a bit of research
on this before yanking out springs from your packs and winding up in a ditch.
John

I don't think he had gotten to that point yet. It seems he was talking about hitting the bump stops on the frame that make contact with the top of the axle just above the spring mount. This is a legitimate concern but he may very well make oil pan to tie rod contact before that.

- EM

earlymopar wrote: ↑

Sat Feb 24, 2018 8:08 am

I don't think he had gotten to that point yet. It seems he was talking about hitting the bump stops on the frame that make contact with the top of the axle just above the spring mount. This is a legitimate concern but he may very well make oil pan to tie rod contact before that.

- EM

It will hit the rubber bump stop on the frame BEFORE hitting the tie rod. That's the whole point of having the bump stop, otherwise, there would be no point for it and it would be a factory design flaw.

Yes, that's normally correct but if he has a non OEM engine or non OEM engine mounts and the oil pan to tie rod distance is less than stock, then contact there is likely before hitting bump frame bump stops.

- EM

earlymopar wrote: ↑

Sat Feb 24, 2018 8:08 am

I don't think he had gotten to that point yet. It seems he was talking about hitting the bump stops on the frame that make contact with the top of the axle just above the spring mount. This is a legitimate concern but he may very well make oil pan to tie rod contact before that.

- EM

Hear you on the bump stop issue. I think if leafs start coming out of those packs, he's risking
more than just one difficulty.

John

Thanks for all the input. I read all the forums and many said to remove leafs 2 and 4 and get a 3 inch drop with no issue, we’ll not true. I removed 2 and 5 to get less drop to be safe and leveled the back by removing 3 leafs out of a 5 pack and my 66 rides like crap. Floats around, body roll and doesn’t steer very good in corners. I have a call into SIDS and I will start over. What do I do with the rear to drop it correctly after the SIDS 3” drop axle. Thanks again for the help!

My 66 lowered itself without any trouble at all - when the Cummins 6bt was installed

Mikelindley wrote: ↑

Mon Feb 26, 2018 4:32 pm

Thanks for all the input. I read all the forums and many said to remove leafs 2 and 4 and get a 3 inch drop with no issue, we’ll not true. I removed 2 and 5 to get less drop to be safe and leveled the back by removing 3 leafs out of a 5 pack and my 66 rides like crap. Floats around, body roll and doesn’t steer very good in corners. I have a call into SIDS and I will start over. What do I do with the rear to drop it correctly after the SIDS 3” drop axle. Thanks again for the help!

The easiest for the rear is to do an axle flip, and place your axle above the rear springs. The drop would be equal to the thickness of the spring pack and 1/2 the diameter of the axle tube. You will need to move/weld on new spring perches, and modify your shock mounts.

Trying to grasp 1/2 of the axle. Seems like the distance would equal the spring pack plus the whole axle width?i would measure from the top of the spring pack where it sits now to the bottom of the axle where it would sit after the flip???? Correct?

Mikelindley wrote: ↑

Tue Feb 27, 2018 9:07 am

Trying to grasp 1/2 of the axle. Seems like the distance would equal the spring pack plus the whole axle width?i would measure from the top of the spring pack where it sits now to the bottom of the axle where it would sit after the flip???? Correct?

Ride height would be measured at axle center. In a spring over configuration, everything below the axle center has no effect upon ride height. In a spring under configuration, everything above the axle center has no effect on ride height.

rear axle flip on mine dropped it 4.75 inches. measured at the rear fender.

You can get a simple, quick and inexpensive 3" drop with these rear shackle drops:


I think I paid $40 at a regular auto parts store.

- EM