My Rearend Hey, Andy, I got the pitman arm.. can't thank you enough. Now I'm trying to find out if I can put a 54 ring and pinion in my 49 carrier and get a little better crusing speed out of ole betsy when she gets back on the road. I bought a 54 rearend for the bendix brakes thinking it would be a one for one swap but I found out that the rearend is from a 54 automatic and the torque tube is shorter than the manual transmission models so it won't swap directly. If the gears will swap I'll have them changed over but I wanted to know what the ratio was before I went to the trouble of having them changed. Wouldn't gain much if I just swaped a 49 4:11 for a 54 4:11 so now I'm happy to learn the gears are 3:90. Thanks again for the answer and the pitman arm.
Craig, You may or may not be able to swap the carriers. It seems that mid-year the carriers were changed out. This is a problem when converting the '54 rear ends to 3.55:1 using the ring and pinion sets available from Patrick's. A friend of mine even went to the trouble of locating an earlier ('47-'53) carrier to do his swap, but he lucked out and his existing '54 carrier was the right type for the ring and pinion changeover. Now, don't get me wrong. This dilemma only applies to swapping out the ring and pinion. It may be possible to swap out an entire STOCK carrier regardless of early or late '54, but I am not certain of that. Andy
Sounds like a lot of effort for a reduction of only about 150 RPM at whatever speed used to require 3000 RPM.
Preperation H Well just my luck. nothing easy. Bill may be right. I'm no expert by any means. I was reading a lot of the posts and trying to get educated and came by some information from a rearend mechanic that indicated that the 3:55 reduced low end torque low speed 'pep' while allowing high way speeds at lower rpm. I asked about a 3:90 and he said it would be a good compromise between the 4:11 and the 3:55 so that's where I was headed. Should I rethink the whole idea and just stay with the 4:11? I'd have $300 in a 54 3:90 rear end I can't use. I'm not skilled enough to set one of these things up and don't have the proper dial indicators and such so it's an outsource job at best. I'd sure hate to get it all there (80 mile trip) and torn down and it not be a 'doable" situation". I guess if that happens I'll just have the mechanic go through the 4:11 carrier with correct torque tube length and install that as I will have already incurred the labor cost for the tear down. At least when he's done I will have a no noise, leak free rearend with the bendix brake upgrade. That's his guarantee anyway. Maybe some more of the forum guys will chime in with some recommendations.
Well Hi I am new to the list but not old trucks I am the owner & Moderator of Old _ChevyGMCTrucks on Yahoo Group My 1954 P/U Built in the Oakland Plant California came with 3:90 Gears sm420 and 235 CID. I changed it to a T55, witch is the 1955 Truck Rear End Open drive line, it was used from 1955 -1962 I than put 3:38 Gears in it with the SM420 transmission At 70mph it Runs like a dream oh and it has the 261 Cubic inch engine do not know the rpm have not put a tack on it but its not turning hard gets 16-17 mpg of gas thats OK in my book. the next thing I am going to do is change the trans to a 700R4 some day Baird-R54
I have not installed them yet but I bought a set of the 3.55 gears from Patrick's. It says that when installing in a 54, you must use the earlier carrier housing so in my mind, the earlier housing should accept anything from the3.55, the 3.90 from 54 or the earlier 4.11 sets. I do know that there are different gear sets for cars and trucks. Let me know if that automatic torque tube looks like it is in danger of finding a new home in the scrap pile.
Gear ratio Hi There Baird-R54, Welcome to this forum. I'm also on one of the yahoo groups for ole trucks. Sounds like you have a highway crusier there. Ah! someday maybe betsy will be out and about also. Gotta get her a new rearend first!!! I puled the cover on the supposed 54 3:90 rear-end today and found a number 32 stamped on the ring gear and someone said if I divide the pinion teeth number into the ring teeth number I can get the ratio. I can't see the pinion to see if there are any numbers on it but if its a 9 tooth l would have a 3:55. So now I'm more confused than ever. More research and help from the forum experts I hope.
my 2 cents the 54 carrier should fit in the older rear end. But you still have the pinion work to do. Bill Hanlon is right, not worth the work for the minmal rpm gain. These engines are all about torque. They can pull taller gears. I have a buddy running a 3:08 rear in his 55 1st 235, and a saginaw 4 speed, it runs real decent. I put 3:55 gears in my 54 and love 'em, but there weren't any choices out there and keep the torque tube and sm420. I still have plenty of rpm's on the road. 2400 rpm at 60 mph with 215 85 R 16 tires with my 235. Read Evan's (coilover) rear-end treatise from a couple of weeks ago, he might convince you to get tall in the back of your long motor. Jim
Rear Gear Jim, Thanks for the tip. I'll go look for coilovers post. What do you mean about still having the pinion work to do? Is it involved?
If you swap the carriers, you still have to swap out the pinion. That's what he means by pinion work. I have 3.90:1 gears in my '55.1. Stock front end. Driving these trucks faster than 50 miles per hour with a stock front end is a scary thing to do. How fast you want to go anyway. Believe me, they are not made for highway speeds and you will know that the frist time you drive it. I am very comfortable driving 45-50 in the slow lane. Don't care how many people give me the finger. Andy
3:90 Rear Gear OKAY, Shuuuu.. Had me scared there for a minute. I was expecting some fitment problem and machine work or some such problem costing lots of money. I will have to ask but the mechanic that's helping me on this can probably handle this as it's his business so unless there is something unusual to deal with he probably knows all about it. I'll let you all know how I make out . It should be a couple of weeks before I can get the parts to him and what ever time it takes him to do the overhaul.
