The Stovebolt Site Forums The Shop Area General Truck Talk torque tube replacement

Hi,
I've been thinking about getting rid of my torque tube on my 48 half ton. I've read that a rear end out of 55 - 59 half ton will work. Is this true? is the 55 -59 rear end the same width as my stocker? I don't have alot of money and would be doing the conversion in my driveway, the easier and less complicated the better. Thank you,Keenan

Keenan, try posting this on the Crash box shop section.
AFAIK the centre section can be swapped out to an open drive.
Just not sure which one though....

I believe you can use the "pumpkin" out of up to a 1962 but someone needs to verify that. However, I do know you can use a 55/56 as I put one in my 52Panel. 485window, I'm not sure abut the 48 but "almost sure". You just pull your axles out, then unbolt the torque tube rear end and pull it out. Then just stick the "pumpkin" back in your housing and use your same axles. I'd probably put a new pinion seal in the "pumpkin" before putting it in and also replace the axle seals...as well as check the axle bearings.
Hope this helps.

A 55-56 will bolt right in and will give you a 3.90 instead of the 4.11 you have now. You will need to weld up the spring hangers because you will no longer have a torque rod. The easiest is to weld them while the torque tube is still in it so you get the plane right.

How much benefit is there with 3.90 over the 4.11? Or is it better to change from the 4.11 to 3.55?

What would be the difference when switching to either the 3.90 or 3.55?

TIA

Changing from a 4.11 to a 3.90 would get you about a 5% improvement

Changing from a 4.11 to a 3.55 would get you about a 16% improvement

Google "rpm calculator" and you'll find a gizmo where you can enter your tire size and rear ratio then see the estimated rpms at different speeds.

Hi Crenwelge,
Thanks for replying to my question.my truck has parallel springs front and back, why would I need new spring hangers? Also, my current rear end has been changed to 3:55 gears. So, by changing to 3:90 gears this will make my 216 rev higher on the freeway? thanks again for your help,Keenan

Hi Achipmunk,
Thank you for answering my post. So, just so I'm understanding you, I can put a 55-56 pumpkin into my '48 rear end?And still use my '48 axles? Does it bolt right in ? Do I need to worry about end play and shims? Could I use a complete rear end out of a 55-56 ? Is it a different bolt pattern? Also, my '48 has been changed to 3:55 gears would changing out to a 55-56 rearend/ pumpkin change my gear ratio? Thank you for your time and help, Keenan

If your rear has been changed to 3.55, why do you want to get rid of it. If you go to a 55 to 57 you will have a 3.90 which will result in higher engine speed. I'm not real sure I understand what you are trying to accomplish. If you look at the spring hangers you have with a torque tube, you will see that you have a pivot at the front of the axle seat. If you take away the torque tube, you have to get rid of the pivot which is most easily accomplished by welding it tight.

I installed a 79 nova. the ratio is not the best but it was cheap and easy to install. how easy you say, i did it myself. that is easy. it has a 2.73 bu i would guess there are others. i have put more that 12,000 miles on it. two trips from indiana to Kansas City mo. and back. no big mountains. but i do have a t-5 with overdrive and averaged 20mpg.

If you already have 3.55 gears................................
THEN LEAVE IT ALONE!
Add gas and drive.
You can certainly change out to an open rear and then have a new driveshaft made-hopefully it balances up on the first shot. And then you need to change the transmission, or at least the rear of it. So exactly how much money did you want to spend to go backwards? Have you actually driven your truck yet? What is the issue? You should be able to do 70mph with that gearing pretty easily. I know a few guys with 3.55's who have run them up over 90mph with your exact setup. The 216 may not like super high revs so 70mph should be plenty. Give it a drive and let us know how it did.

pete you make me sick

Should I tell him what a Truckstell and 3.55's can do?

you forgot to mention 302 all i remember is 302 + 3.55's + truckstell = cleared for take off anyone wanting to go any faster in this old steel should consider buying a lear jet

When you go to the open drive - what you going to do with the 3.55 gears?

"what you going to do with the 3.55 gears?"
Exactly. You do realize that the previous owner spent over $600 bucks to put the 3.55 R&P into that truck. Send that old thing to me if you don't want it!:)