The Stovebolt Site Forums The Shop Area Engine Shop Who has used Patrick's rearend gears?

Yesterday I took my 53 out for the first time. Took it to the DMV to have inspected and get tags. The rearend gearing is my next issue to address.

I am going to the "open drive shaft and mid 80's Blazer rearend" on my 46 that is down to the frame. But, the 53 is looking and running too good to take apart all the way back to the motor right now. I also want to keep the 3 on the tree. Finding donor rearends and trannies is way too hard around here as well as time consuming.

If you have done the 3.55 Patricks swap, please fill me in on all you can.

Mark

Mark, I have the Patrick's 3:55 gears in my truck..

To me it was the best money I spent on any part of the truck. The swap was pretty straighforward. If you are patient and can follow directions you should not have any trouble. You will need a dial indicator to set up the lash on the ring and pinion. I found the instructions in the shop manual easier to follow for that portion..

There is a picture of the disassembled torque tube housing on my web page, click on the link below.

Any other questions, let me know.

Travel in the Fast Lane with Patricks 3:55.
They work great !! & can make that truck go faster than it ever was designed for.

Bill & MT,

Does the torque tube have to be removed from the rearend or can the swap be done entirely thru the back cover?

By the way, Bill, great website you got there!

Mark

Mark, the torque tube has to be removed. If you notice in the picture, I made up brackets to hold the tube to the sawhorses.. Take a piece of 2 x 6 and drill a hole through the middle that approximates the diameter of the torque tube.. Rib it in half on the table saw. Screw it in place with a few sheetrock screws. That will hold the tube it place while you are working on it..

One other thing. I pulled mine all apart and checked the condition of the bearings ( axle and carrier ) before I ordered the parts. In my case, the rear end had recent work so the bearings and races were all in great shape. Patrick's has the bearing kit if yours are worn..

You will also need new gaskets for the rear differential cover the the torque tube housing. Patrick has those as well. When you call, try to talk to Patrick Dykes himself. When you get near the end of a large order, he tends to throw in a part or two, he picked up the shipping on my order as well..

Mark,

I put the 3:55.1 kit in my '51 last summer. I highly recommend it if you are planning on keeping the truck stock. I just got through putting a fresh 235 in a few weeks ago so now I'm ready for summer cruising.

One thing I have noticed though. With the three speed and the taller rear end it is a little doggier at low speed. I think a four speed would do better. especially if you haul or pull anything.

I looked at Patrick's site, looks like $399 for the ring and pinion and $275 for the installation kit. Is the kit required or is it one of those "nice to do while you are there" things?

Mark

The kit isn't required, but recommended. It's not pleasant to have to go back in and tear it all back down to replace the bearings.

Mark, I mentioned in my post above that I tore mine all apart before I ordered the parts. My carrier bearings and races, axle bearings etc, all happened to be in great shape. I only ordered the ring and pinion, shims, axle seals, and the housing gaskets.

Fred is right, you will have all the parts in the installation kit in your hand during the swap. I would only want to do the job once if it were me..

A friend of mine in the parts business priced all the items in the installation kit and found that he could not buy them any cheaper than Patrick's.

A 10 bolt Chevy truck center fits you have the use the old side gears and change the upper and lower
studs in the housing.It's cheap,quick,and easy

J.H.

What year truck did that rear come in? What is the full procedure? Need all the info possible. Is there a previous post about this?

Mark

Mark.....you need a 55 up 10 bolt truck dropout
Pull all the old torque tube and drop-out
Change thw two top studs to the longer ones from the 55up.....and the two lower

Put the 55 center in your original housing put the original side gears in and install your axels

Put on the tires

Put the truck on the ground

Pick your driveshaft angle

Stitch-weld the pillow blocks so the whole darn thing doesn't fall and 'PO GO' you

That's it!

I did this on my '51 way back when, with a '59 pumpkin. Gearing went from 4.11 to 3.90, hardly worth the effort - are there taller gears in later versions?

Re Welding up the spring perches (pillow blocks) Be sure your welder knows how to weld cast iron. Mine fatigued and broke after about 10K miles.
exciting handling with only the shocks, shackles and U-joint holding the rear end in place..!

Sixpack.....I went from dead 4:55 to good 3:90s
Then first a 18% O/Drive and next a 25%....it's really good if you have the power and torque

I think there are other ratios but less common that 3:90

Remember the pillow block welds don't look pretty
I made several passes and really stuck it!

Do you remermber that all this was cheap and easy?

Me too....That's why I mentioned it

How much better would the 3:55 gears be vs. 3.90 in a 58 Stepside with 235? The 3:55's are about 9% higher but will that make much of a difference in highway driving vs. going from 4:11 to 3:55, a jump of almost 14%.

Does anyone know what RPM a 235 would turn at 50MPH for the different ratios? All with a 3 speed and standard 6.70X15 tires.

I have 15" wheels on the 53 and three on the tree that I want to keep. When did the 3.73 rear come out and would those gears interchange with the old rear housing and torque tube? I am putting a K-5 4WD Blazer 3.42 rear in my 46 behind a Borg Warner 5 Speed w/OD. Don't yet know how it is gonna work behind the 261.

Kinda sounds like either Patrick's gears or replace the torque tube/rearend setup. Or don't mind the line behind you!