Axle bearing question

GPster · February 17, 2015, 10:44:57 AM

Quote from: "Beck"
Quote from: "wayne petty"leaning out to assist steering.. creative. almost makes necessary to use a rear steering axle. like was used on chevy trucks a few years back..

is the hitch mounting point adjustable. so you can control the front lifting and the rear lifting.. might be as easy as building it on a triangulated pivoting bar.. with a jack screw to change the height..

Rear steering doesn't help much. The idea is to get the front of the tractor pointed in the direction you want to go. With rear steering the rear tires of the tractor are pointed down the track but the front is now trying to be the rear because it is still going the other way.

Maximum hitch height is listed in the rules. The higher the hitch the more down force on the rear axle. The axle center line to hitch hole is not in the rules. It also makes a difference. The longer the hitch the more leverage. This has to be combined with front weight to just get the front tires to float. If the front of the tractor comes up too high the hitch height goes down. All tractors in the class pull with the same chain of a specified length. We are required to run wheelie bars. If the front lifts to far force is placed on the bars and traction is reduced. With a small tractor you can lean forward and back to do some balancing.

Tractor pullers all want "moveable weight". That is weight that you can move from front to rear on the tractor to try to tune it to the track conditions. Some dirt has more traction so you want more weight on the front. Some is loose so you want to put the weight in the back. It is all a "best guess" before you make your pull.

It's a shame you'd have to use the friction of the brakes.you could use an ABS braking system with a computer to slow down the faster wheel. GPster

Beck · February 17, 2015, 10:54:45 AM

GPster,
That is way above my level of expertiece.

GPster · February 17, 2015, 12:30:43 PM

Quote from: "Beck"GPster,
That is way above my level of expertiece.

I have no expertiece (I can't spell it either). I only have dumb ideas. GPster

jaybee · February 17, 2015, 09:03:16 PM

Sure, I'd love to see pics of the build. Yeah, it's sort of special interest but it's certainly a hot rod, and you never know what might contribute to something that runs with license plates, or on the drag strip, or the salt flats, or anywhere else.

unklian · February 17, 2015, 09:35:30 PM

Quote from: "jaybee"Yeah, it's sort of special interest

Yes, very interesting.

papastoyss · February 18, 2015, 03:07:09 PM

Quote from: "Beck"Wayne,
I did consider all of your options before starting.

I am using the stock mounting points as in your photos. I removed the rubber bushing at the pinion and made a steel one. The cover mounts will also be solid.

A lot of the vehicles I was looking at had the hubs removed already, and others had bad bearings in them. That kind of scared me. Another concern of using the Explorer hubs was the top mount. It is like the pin of a ball joint. It doesn't provide much turning resistance. I like the hub design of the Lincoln LS better but the wheel bolt circle on those is only 4.25". The axles may be smaller also. The Lincoln LS hubs are aluminum the Explorer are steel.

After much consideration I decided there were more moving parts to rob power so I went with the conventional axle design. I even considered moving the center section forward a little and letting the CV joints angle forward. This would shorten the distance from the axle center line to the hitch hole.

I wasn't sure how much abuse the CV joints could take either.

Alignment is critical when abusing CV joints. In the late 70s I ran a NHRA L/G Fiat w/VW engine & transaxle.We took the bearing hubs from VW trailing arms & welded them to a tube shaped like a dropped axle in order to use a 4 link rear suspension. When the tube would flex enough to put the CVs in a bind the result was a broken CV joint on the starting line w/an 8,000rpm clutch sidestep and a locked (spool) diff. Is there any reason you can't use a narrowed 9" Ford axle, esp if the whole assy. is to be welded into the frame?

Beck · February 19, 2015, 11:05:13 AM

Quote from: "Beck"
Quote from: "enjenjo"
just use the 9" axles, and have Moser respline them for the length you need. If the axles are short, any 28 or 31 spline axle is big enough for 31 splines. Moser, last time I checked, got $80 plus shipping to respline axles.

The Explorer axles are smaller between the bearing surface and the splines. I thought the 9" axles were also.

I was wrong. The Explorer axles are NOT smaller in the center. I saw the center was smaller than the outboard axle bearing. It is not smaller than the spline OD.

enjenjo · February 19, 2015, 12:05:24 PM

Quote from: "Beck"
Quote from: "Beck"
Quote from: "enjenjo"
just use the 9" axles, and have Moser respline them for the length you need. If the axles are short, any 28 or 31 spline axle is big enough for 31 splines. Moser, last time I checked, got $80 plus shipping to respline axles.

The Explorer axles are smaller between the bearing surface and the splines. I thought the 9" axles were also.

I was wrong. The Explorer axles are NOT smaller in the center. I saw the center was smaller than the outboard axle bearing. It is not smaller than the spline OD.

Once you get 4" behind the original spline, all Ford 9" axles from 1970 on are big enough for 31 splines.