New Guy with a question

[HeloTech]

Hey everyone,

I'm new to the forum and have a question for you.

I'm actually investigating this for a friend who has a "new to him" T-bucket.

he's not very mechanically inclined so some of us are trying to help him get it to a point where it's safe to drive.

the bucket was basically something some one threw together without doing a lot of research first.

it's a home built frame with a fiberglass bucket on it

here's what I know about it so far:

SBC motor
TH-350 tranny
ford 9" rear end with motorcycle coil over shocks for the rear suspension
1961 ford econoline I-beam axle, spindles and drum brakes (best I can tell)
transverse leaf spring on the front

when he got it, it was pretty much un-drivable. I changed the caster from 0* to 8* neg. then squared the front and rear axles to the frame, the I changed the toe from 1" in to 1/8" in. all this got it to where it steers ALOT better.

we went through the brakes, adjusted the shoes on all four wheels, then bled everything, seems to stop pretty well for being 4 wheel drums

the biggest issue right now is the ride quality, I know these don't ride GREAT but I think it should be better than it is, from reading on here, I'm sure the rear coil-over shocks aren't helping but the biggest thing is the front end, it's kind of scary when your driving down the road and hit a bump the front end jumps and the tires leave the ground for a moment, when they land the car pretty much goes where it wants to. I also think the front spring is WAY to stiff, and honestly I'm not sure it's even the right length.

can someone give me some insight on how to properly size the front leaf spring. I'd like to help him get this thing right.

thanks,

 

[Francis Blake]

The first question I would ask does it have shocks on the front end? It sounds like it may need a pan hard rod in the front. It sounds like it may have a bad case of bump steer, that is a condition where the front wheels can turn where they want to on their own while turning or hitting a bump. A pan hard rod should correct this.

 

[HeloTech]

thanks,

and sorry I forgot about a couple facts.

it does have shocks on the front and it uses rack and pinion steering, it's my understanding that with the rack it shouldn't need the pan hard bar (I could be wrong though).

 

[choppedtop]

Check air pressure in the front tires also. To much will bounce and be rough. What is the front tire size? I would add a pan hard. My front end does almost no movement bump wise. It is a bit clunky when I hit sharp bumps, but low air pressure helps a lot. Are you sure those are m/c coil over shocks on the rear, or car coil overs?
Lee

 

[bobs66440]

Yes, tire pressure makes a big difference. I'm running 22psi in 165/80 - 15 tires in front and 18psi in 235/70 (or 75) in rear. Make sure the shocks in front are good . Bad shocks will act like no shock at all. It may be over sprung. Jump on the fornt and see if it moves or if there's any binding. Having some type of location device in front like a panhard is important, even with a transverse front setup like 99% of the buckets have. Go over all the bolts and make sure all connections, bearings, king pins etc. are tight. Make sure there is no play in the steering linkage. Make sure the front end geometry is designed well.

 

[fluidfloyd]

thanks,

and sorry I forgot about a couple facts.

it does have shocks on the front and it uses rack and pinion steering, it's my understanding that with the rack it shouldn't need the pan hard bar (I could be wrong though).

If that R&P is mounted on the frame then there is a very good chance he has bump steer issues. If it is located on the axle beam then he should be pretty good. Pictures would be of a big help.

George

 

[fluidfloyd]

HeloTech Quote:

"ford 9" rear end with motorcycle coil over shocks for the rear suspension
1961 ford econoline I-beam axle, spindles and drum brakes (best I can tell)"

HeloTech,

Check the diameter of those rear coil springs. If they are 3 1/2" outside diameter they are in all likely automotive units. Motorcycle will be a much smaller across the coil diameter.

Also noticed he is using a traverse mounted spring with an Econoline front axle. This tells me he has welded or bolt on spring mounting brackets. What about front shocks?

George

 

[Zandoz]

George hit on what came to my mind...the R&P steering. They are prone to bump steer if frame mounted, but that can be minimized with the correct configuration. If there is no panhard or other side to side locating device, it will add to the bump steer issues. Make sure the center line of the rack is in line horizontally and vertically with the connection to the steering arms. There are others here who can give more thorough advice on R&P set up.

 

[HeloTech]

thanks guys,

sorry for the lack of info about it, but I'll try to find out more next time I see him.

I've got a couple pictures but they're not very good and don't really show much of what I need to know.

I"m pretty sure the rear springs are M/C just by looking at them, they have an adjustment collar on the bottom of them that uses a spanner wrench to turn which raises and lowers the ride height (I think) and they're pretty small in diameter but VERY stiff.

the rack is frame mounted and I know it is now where near in line with the steering arms, in fact, it looks like someone has bent the arms to get through the hair pins.

I'm fairly sure the front tires are running normal pressure (32 psi) but I'll have to get him to check them.

I know we've discussed the rear pressures but we need to figure out something for the valve stems so we can get a gauge on them, they are VERY short, maybe and extension.

as I stated earlier, this is just something someone threw together and didn't spend alot of time planning first. I think it's something we can get right eventually though.

last I heard we are planning on tearing it appart over the winter and pretty much doing a rebuild on the car, we'll go through the motor, clean up some ugly welds on the chasis and have it blasted and powder coated, then stip and repaint the bucket along with a new wiring harness.

hopefully I'll have enough info by then to correct some of the flaws in the build we've found.

 

[bobs66440]

Good idea. Many times it's just quicker and easier to start from scratch than to try to modify a bad design.

 

[Ma_n_Pa T]

HeloTech, first off lets get it clear on what the front end is doing, is the front tires leaving the ground and bouncing up and down, if so that is not bump steer, side to side is bump steer, if its bounce let some air out and you could have a very stiff spring.

I run a frame mounted R&P and have done for 7 yrs with no problems, front tire have no wear in 15,000 miles and it drive good, yes you do have to run a pan hard bar, any side steering car you need a pan hard bar. If you or anyone else would like to see the mounting of the rack, PM me your email and we will send you some pic's. I do not have the pics on a site that I can post from to here.

 

[HeloTech]

thanks guys,

the car tracks straight while on smooth roads but is very sensitive to steering inputs, when you hit any decent size bump like a man hole cover or road joint that is pushed up any, the front wheels either come off the ground or get VERY light, when it looses contact the steering becomes pretty unpredictable. I have to stand on the front frame and jump to get any deflection out of the front spring (and I'm a pretty big boy), so I'm pretty sure the front spring is way too stiff for this car.

I'm not sure what you mean when you say "side steering" car? the rack is frame mounted and has each end connected directly mounted to each spindle arm (no cross rod).


does anyone have a resource for setting up the proper steering geometry for a setup like this? as I said we will be rebuilding the frame/suspension this winter so it shouldn't be too bad to correct (if I know what to do).

also, does anyone have a procedure/guide for selecting the correct spring for these cars? I can't go by what axle is in the car because it wasn't designed for this application. it's been modified for using the transverse leaf spring but I doubt it will be any "common" spring set.

thanks for all the help with this, my buddy loves the car and he's like a kid in a candy store when he drives it---but---I think it scares him between the rough ride and the steering issues, I'd love to help him get this straightened out.

 

[EX JUNK]

Side steer does not apply to a rack and pinion set up. The first thing that I would do is to lower the front tire pressure to around 24 pounds or so and then I would try to eliminate a leaf or two from the front spring. I believe that those two items would go a long way to improving your problem.

Jim

 

[T-Test]

Send pictures and maybe we can help. guessing isn't good for this type problem. Set toe to 1/8 out to begin with and lower tire pressure to 25 or so. Pictures will be required for all rest of the diagnosis.

 

[HeloTech]

thanks, I'll take some and post them as soon as I can get to the car and do it.

right now it's set to 8* neg. caster and 1/8" toe in

 

[EX JUNK]

thanks, I'll take some and post them as soon as I can get to the car and do it.

right now it's set to 8* neg. caster and 1/8" toe in

I believe in having a "toe in" setting rather than toe out. Both my cars are set that way and they handle superbly.

Jim

 

[baddawgcustoms]

thanks, I'll take some and post them as soon as I can get to the car and do it.

right now it's set to 8* neg. caster and 1/8" toe in

I'm a little new to the t bucket building, but typically I'm pretty sure most of these cars are setup with positive caster (top of the spindle angled back) not negative. I was advised around 8 degrees positive for mine by the guy who built my front axle. I don't think that would have anything to do with the wheel bouncing but I'm sure it will effect steering quality. Maybe someone else can chime in on the caster, neg vs pos.

 

[HeloTech]

Hey Dale,

it's probably a misunderstanding on my part, the top of the axle is leaning back, I meant to say possitive and mis-spoke.

 

[choppedtop]

Whew,, ya had me going on that negative comment. Not sure about camber numbers, but I know my tires/wheels are a bit leaned out at the top. I bet somebody here knows.
Lee

 

[bobs66440]

Mine has 7 deg positive caster and 1/8" toe in and handles very well...