...On my Frame rails and taking a chance of tearing them up - SO I decided to make me 4 frame rail jacking pucks that attach to the rails on all 4 corners and allow easy, painless jacking points to lift my FD without destruction. These are made of 4" wide X 1" thick solid aluminum that I cut and "milled" a groove down the middle to allow it to fit up around the rail. It has 4 - #10 ss sheet metal screws that hold it onto the rail. I also made a 2" round cap that fits in the center that allows the jack to center itself and a place to hold onto and not slip. It took me around 1.5 hours to make up all four using a bandsaw, drill press and 4.5" grinder as the primary tools. Worked out great. Now no more worry about ripping out the rails when lifting the car, and they stay put and weigh almost nothing. I have plenty of this 4" bar left and can offer them to others that may be interested - just pre-cut only with instructions on how I cut the groove and mounted them. E-mail me for specifics.

 

Very cool. Job well done. Great idea. Are they visible on cars without any kind of body kit (looks like you have one on yours)?

 

Umm....I would buy a better jack or just use a block of wood (or jack the car at the crossmember) than drive around with large blocks of steel screwed to my frame rails.....but that's just my opinion.

 

Umm....I would buy a better jack or just use a block of wood (or jack the car at the crossmember) than drive around with large blocks of steel screwed to my frame rails.....but that's just my opinion

Not steel - aluminum and you cannot even see them, even if you lay almost flat on the ground. My car is lowered and a jack will not fit under the crossmember. Fit under the frame rails perfect.

Tom

 

how about some air jacks? I'd like a set of those.

 

Just FYI, those are called "pinch welds" not the frame rails. Really unless your using the stock jack for emergency purposes you shouldn't jack there at all.

The diff is a good place to jack the rear, the frame rail(s) or crossmember is a good to jack the front. If you use a jack with the little steel "teeth" it is a good idea to use a piece of wood so the teeth don't dig into the car.

 

Although it seems like a good idea, I would not use them. There is potential for the aluminum to split where you have cut the groove.

 

Let's do the math on that...

4" long by say .125" wide = .5 sq in surface area for the body to rest on the aluminum. Say you were crazy and lifted the entire 3000lb car up with one block.

3000lb/.5 sq in = 6000 psi stress. Well below what you need to worry about splitting the block.

 

What you did is cool, it spreads the load out evenly but a bit of overkill. I did the same thing by taking a 1.5" thick x 3'" wide x 4" long piece of uhmw, grooving down the center, and placing it on the puck of my floor jack. Same effect, lots less work

 

Maybe I'm kookee but 3000 lbs/ 1/2" is 1500 lbs per1 square inch

 

Maybe I'm kookee but 3000 lbs/ 1/2" is 1500 lbs per1 square inch.

 

No it isn't. Do the math again. Dividing by a half is the same as multiplying by 2.

-Max

 

That is what I do, I use a 3 foot long piece of treated 2X4 so I dont put alot of stress in one place of the frame, unless I get stuck on the road and have use the OEM jack, I don't drive around with a 1 ton jack and a 50 lbs piece of wood in my car.

 

I'm not following your math Jeff.

The block was 1" thick. He cut a groove in it that appears to be about 5/8" deep. Maybe I'm wrong, but I'm thinking that the block is likely to split along the groove because it has been weakened, and the weight of the car may cause it.

 

Adam, you and Jeff are talking about different failure modes. Jeff is comparing the pressure caused by the weight of the car to the yield stress of aluminum (whatever alloy he used, there is no way the weight of the car will cause it to yield, even around the stress concentrations at the corners of the groove). Your concern is legitimate that repeated loading could lead to crack propagation at those stress concentrations and eventual failure by fracture, but he'd have to jack his car up and down on the order of 10's of thousands of time for that to happen

 

Where did you find the miracle jack that will actually reach either the diff or the front crossmember on a lowered FD? I have to first jack one front wheel, and put it on at least a 4-5" lift (block of wood or something), and then I can barely get a jack under the x-member. I can put a jack barely under the diff, but i can't move the handle more than maybe 1/2" at a time.

If you've gotta get the car up quickly, you've gotta jack from the side. I've been thinking of similar ways to protect the rails, and ended up making two 2x2" pieces of wood that run the length of the rail, jack from the center (you can do that with these cars), and slightly rounded the ends for the stands.

 

http://www.ultimategarage.com/acjacks.html



Or you can just invest in a couple 2x6s to drive up on so that you can use a regular jack...

 

What he said.

AND

What I said, don't worry about it.

 

4" to 5" blocks?!? Man those are HUGE!. I can't jack my FD up with my low profile Harbor Freight jack unless I drive it up on about 1" blocks I have no problems.

The pinch weld is a semi strong part of the car. Yes you can lift it there but lifting under the front frame rail is the best place. Look for a spot next to the DP/Precat that has the factory undercoating wiped off it (mirror image other side), that is the place to jack from. Steel teeth on a jack will still dent them, use a flat faced jack like Jim suggested or checkout the Harbor Freight special.

 

I love this forum, full of scientists and philosophers...anyway, they won't bust, break, fall off, cannot be seen, rot, splinter, and not fail to raise the car.

Tom

 

I just keep a supply of 4" square pieces of 2x4 scrap that I slot across the grain (else they split). They work fine with the jack and with jack stands...

 

Even with Eibach springs on my car, I don't have any trouble. I use a small floor jack first - stick it in between the front passenger side wheel and the rear of the fender to get to the front A-arm. I jack that up a bit until the tire is JUST about to totally come off the ground. Then, I can get my big floor jack under the front subframe, fully jack that up, and put jackstands on the subframe. Then, go around to the back and I can easily get the jack under the differential and put it up on jackstands.

Takes very little time to get it up like that.

A car that's bigtime lowered (coilovers, etc) will have more problems of course. But, that's the price you pay if you want your ride slammed .

Dale

 

I applaud your attempt to make something new and useful. I think its a cool idea. I personally wouldnt use them, but thats ok. Unless there were some huge inner cracks in the aluminum, i cant see it ever breaking due to cyclic loading. As for yielding the aluminum, Aint gonna happen!
Adam

 

Dale, I've always been reluctant to jack on the A-arm or other suspension points due to the fact that 1) they're aluminum and I figure they'll get chewed up 2) suspension flexes so is inherently unstable. 3) I've read not to

How do you protect the aluminum and/or keep the jack from potentially slipping? (sorry, just trying to picture what you could get to from behind the front tire - not by my car atm... *sigh*)

 

Don't you love it when engineers get together in one room.