Rear end housings in funny car vs. top fuel (1 Viewer)

[.]

I have seen 2 kinds of fuel car rear ends in both kinds of cars and was wondering why such different designs?
Here are examples of both:

What are some of the determining factors to choosing one design over the other in a top fuel chassis?
..and a funny car chassis?

 

[Toby]

Mainly crew-chief preference. Strange and Christman are the main suppliers and the two in the photos. Chirstman on the top pic

 

[.]

I saw the Baca crew checking gear tooth pattern the other day.
The whole top of the housing is removable. Looked convenient but bulky.

Being unfamiliar with the other version, how is it done on that one?
Is that case made of billet?
Looks much smaller.

I wonder what might be the fully loaded weights on both units.

They have pumps inside them right?

 

["Dr. Dirt"]

We run Strange Top Loaders in all four of our cars. They are a scaled-down version of the Strange T/F unit. The removable top is handy for servicing but, as I understand it, it is not considered as durable as Steve's units. The Chrisman unit you show in Mike Strasburg's car is the most widely used and yes, they are billet units. You can stop by their shop and watch Kevin cutting them out of a block of aluminum in their awesome CNC machine. The design is considered nearly bullet-proof.

 

[Bullet]

Do they run the same design ring and pinion gears?

They have pumps inside them right?

I don't think they have any pumping mechanism in them. I always thought that they utilized splash/submerged method of lubrication.

Anyone?

 

[Mooseman]

Chrisman Driveline Components - Custom Rearends

Strange Engineering Catalog - go to the live axle assemblies section and look at the 12 inch .

They work just like any other diff just are horrendously strong

 

["Dr. Dirt"]

Do they run the same design ring and pinion gears?



I don't think they have any pumping mechanism in them. I always thought that they utilized splash/submerged method of lubrication.

Anyone?

Paul's correct here. They have no internal pumps. Now, the NASCAR boys do to keep things cool for 500 miles of load but ours can handle 1/4 mile without concerns. It should be noted that launching full tilt on cold gear oil can cause catastrophic failure even in our sportsman cars. That's why you'll see everyone from sportsman cars to Top Fuel allowing the tires to spin during warm-up. Gear oil is usually hearty enough to hold heat from warm up to the launch. Problems start when you have to sit in the lanes during hours of cold rain which you would remember better than most of Mr. Flores.

 

[.]

It was a bit nippy.

thx for the links(again) William

I definitely saw metal tubing in the housing. Like brake lines with fittings.

 

[.]

Yes, the 2 different models of the 12" Strange (big show) rear end do have internal oil pump provisions.

Click this link to read the description..... It's page 142 of the Strange catalog.
http://www.strangeengineering.net/catalog/142.html

 

[Mooseman]

My guess is its personal preferance , sort of like choosing between a SSI made Blower and a PSI made Blower both do the same job but made by different people .

The Force teams all use strange stuff but my guess is thats because the Chi-town hustler had strange stuff so Coil would have chosen the parts he was used to when joining with Force .

I have no idea what is better or stronger you would have to ask the people that use the stuff . I do know that the Strange top fuel/funny car diff has around a 20 grand new price tag .

 

[Bross Hawg]

Do they run the same design ring and pinion gears?



I don't think they have any pumping mechanism in them. I always thought that they utilized splash/submerged method of lubrication.

Anyone?

The Strange unit has an oil pump...has pressured oil to front pinion bearing and both outer axle bearings...rebuilt em (new ring and pinion) every 30 runs max on Medlen's car...

 

[big guy]

Both the Strange and the Crismon are designed to go 100 laps without service.Some teams do it sooner (personal preferrence).I have seen some go almost 200 without any ring gear or pinion problems.Both have 12 inch ring gears.

 

[Mooseman]

The Strange unit has an oil pump...has pressured oil to front pinion bearing and both outer axle bearings...rebuilt em (new ring and pinion) every 30 runs max on Medlen's car...

That would be to stop heat build up right so that they dont sieze under friction? would also help them remain oiled under acceleration right?

 

[Nitrohelper]

......my guess is thats because the Chi-town hustler had strange stuff .............

In old days Austin worked at a car dealership ,he would work at night for Bob building rear ends.
The Hustler also received some funding from Bob even before the Team Strange deal.

 

[unclebob]

Do they run the same design ring and pinion gears?
I don't think they have any pumping mechanism in them. I always thought that they utilized splash/submerged method of lubrication.

Anyone?

P.R., and those into technical stuff;
Although both have 3.20 ratio-12" gears, there is a difference in how the pinion is supported. The Chrisman 10.5" & 12" has what we know to be a 8"-9" Ford style "tail bearing" at the back of the pinion gear.
The Strange 10.5" & 12" do not have a "tail bearing", but have a much longer pinion shaft with massive bearings.
The Strange units can be ordered with a mechanical oil pump.
They do not interchange.
There is a lesson to be learned here about oil. For those who have ever watched an outboard motor in a barrel, all the oil gets thrown away from the pinion bearings as the pinion gear acts like a prop, and it all goes to the top-back of the housing. You must not run too little oil/lube!

 

[ricko999™]

Speaking of rear ends and running short of 1320ft, it makes you wonder if someone will or has "covertly run" a 3.30 or 3.40 ratio.
RO

 

[Bross Hawg]

Both the Strange and the Crismon are designed to go 100 laps without service.Some teams do it sooner (personal preferrence).I have seen some go almost 200 without any ring gear or pinion problems.Both have 12 inch ring gears.

Umm...running at the level we did at Force's, we were seeing quite regularly cracks in the teeth on ring and pinion, mainly the pinion. We used to go 50 runs and rebuild, but changed to 30 as more safe than sorry. As the clutch and rear end guy, I really did not want one coming apart. 30 runs was a major PITA, as you never have enough time to do what you need to do. We had 3 rears, and would do alot of swapping. I think the main reason for pressured oil to bearings is to keep it all from going to the rear of the housing under accelleration. It feeds the front pinion bearing first, and then the outer axle bearings.

 

[Buzzz Miller]

Speaking of rear ends and running short of 1320ft, it makes you wonder if someone will or has "covertly run" a 3.30 or 3.40 ratio.
RO

That would take an act of congress to get the makers of gears to make that ratio for a 12" rear. If someone was to order some, the minimum order would be quite substantial. (They have tried that for the a-fuel stuff.)
Word would get out that they have been ordered months before they could even be made, and people would know. Kindof like the 20" wide top fuel wheels. The techs were awaiting them before they ever got to a national event.

 

[.]

Thanx very much Bross!

Do pumps ever fail?
Are they easy to swap out?

After "x" amount of runs, do teams throw the components into the trash?

Do any components get X-rayed? (I might be confusing that process as "magnafluxing" ..... like with cranks)

Thanx again.

 

["Dr. Dirt"]

Do any components get X-rayed? (I might be confusing that process as "magnafluxing" ..... like with cranks)

Thanx again.

Given the cost of new Ring & Pinion sets and the expense of blowing them up and hurting your case/housing, running used gears is never an option for us lowly sportsman guys so I highly doubt the pros would trust the transference of their 8000 HP to used gear sets. Every team I know has a set number of runs prior to discarding them.