'59 Plymouth Forum

Hello All,

Can anybody help with the following question? My Fury has the stock 2.71:1 (non sure grip) differential. Is it possible to use the same housing and convert it into a sure grip differential, or is this a completely different housing?
Thanks to all.
Stefan

Hi Stefan,

I have put a 3.31:1 Sre Grip in my Belvedere convertible in the same housing as a conventional 3.18:1 (from a 58 Plymouth)and it works just fine. The only thing to be aware of is the Shure Grip axles are shorter than conventional so you must keep axels and differential together as a set. The conventional axels are only 1/8 of an inch longer each, but that is too much to obtain correct end play with the shims. Unless you have enough additional shims to stack 1/4 in high, (1/8 on each side) then your conventional axels will work.

Tom

Boy after reading my post I'm sure you guys wonder if I'm sure how to spell Sure.................

Hello Tom,
I’ve waiting for some days but no further answers came in here. I guess there are not very much people out there who know about this details.
If I do understand you right, then it is possible to use the conventional, non "sure grip" housing, remove the differential from inside and convert it into a sure grip differential. Is that right?
Tom, where can I get the parts to do this conversion and do you have a glue how much it may cost? My ring and pinion gears are worn out and I need to do something.
Thanks
Stefan

Hi Stefan,

For what it is worth...

I used an entire rear end assembly from a 1976 Plymouth Volare that had a 318 V8 motor. It is a 3.23 to 1 Positraction rear with a smaller housing (I believe 8 1/4 inch). The smaller rears are great unless you plan to go racing or have a high horsepower motor. It was an easy swap and there are many of these available for low $$$$. The side to side width was almost identical to my original 2.91 rear.

Good luck in your exchange.

Curt in Ellicott City MD

i wonder if mine is limited slip, it did come out of a cop car w/ police package, i'll have to check. didn't even think about it, would be an added bonus if it did, but if does have it, probably has burnt clutches because i don't remember the tires locking. mine came out of an '89 diplomat, everything fit beautifuly, except for the later model springs, front eyelet was different shape. i just removed the top leaf from the original and the donor and attached the donor lower leafs to the main original leaf, seems to be alright. what can i say, i'm redneck . i know that jc whittney sells leaf springs, but for early 60's up. my question is, will the '59 interchage with "later model" springs?--jeremy

Hi Stefan,

Yes it it the same housing. I don't know of a conversion other than sourcing a complete Shure Grip differential and axels from a donor car and replacing yours with it. If you do this be sure you have some axel end play of .013 to .018 inches. This is accomplished with the shims.

Sure Grip axels are indentified by means of the letter "S" stamped on the ratio pad on the bottom of the carrier housing.

Good luck, Tom

Tom,

Thank you for this information! I’ll come to the US next year and if I have a little luck I’ll find a sure grip differential for my car. Crucial was to know if I can keep my housing or not and of course the subject with the rear axle. Thanks again!

Curt & Jeremy also thank you for your input. It’s always interesting to know in which these parts are also hidden.

Stefan

Whats the best swap for the axle then?
Lets say its a later suregrip, a late 60s early 70s type, which will fit widthwise to look stock? Will a late 60s barracuda one fit? What about a mid 70s cordoba?
What about stronger rear springs has anyone fitted somthing a bit stronger that gives stock apperance?

Made the swap succussfully! For anyone that wants to know---Late 60's B-Body axles and housing(mines from a '69 Charger), B-Body SS Springs-both Left side for 3800# car(M.P.), A-Body rear shackles, relocated the spring pads on the housing, drilled out the bolt hole on the front perch(B's use larger dia. bolt), use the later C-body length shock--use 741, 742, or 489 case centre section and Bob's your Uncle!