P18 rearend swap

[Booger]

Back in the game with my new 49 SD P18

50 years ago I found a R10 OD it was an ez swap

I'm learning those are impossible to find and I'm not spending $2000 for one

but I understand a Ford Exporer 3.54 or 3.27 is a option to get freeway cruising speeds

so my question is ..is this a better option?  Can a backyarder do this?

[Andydodge]

I can't give a specific answer whether the rear end swap is absolutely a better option but unless spending $2000 is fine I'd think the rear end swap would achieve a better  and cheaper result...........main thing with any rear axle swap is to check that the brake drum flange to flange width is within the specs of the original rear end, generally 1-1.5" extra shouldn't create a problem with stock width wheels, the Frod rear end should have the same bolt pattern, a handbrake assembly if wanted and also check the actual brake set up........is the Frod brakes disc or drum.........with a stock mopar front drum then the ideal is drums on the rear as well.........as for the actual swap, jack it up, use proper jack stands and wood blocks as well if possible........you want the car to be solidly and securely off the ground and SAFE for YOU to get underneath often............remove the stock rear axle, slide the Frod one in, centre it, get the pinion angle correct, 2-3degrees up towards the trans, check where the spring hangers sit, move or adjust/cut or remount  them to suit the springs, you'll also need the Frod driveshaft and have it shortened to suit the Plymouth slip yoke or ball & trunion(yuck, I'd replace these mongrel things with a proper uni joint if possible).....and new brake lines to the new rear brakes........and thats about it............lol..............a backyarder can do this , just take your time and get everything before starting .........regards.......Andy Douglas  

[derbydad276]

Jeep Cherokee rears  3.07 gear .. 3.55 gears 

 

https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

Edited January 7, 2020 by derbydad276

[48ply1stcar]

I haven't done the rear end swap yet, but there are plenty of threads on this site with completed swaps.  After all of my research I have deceided on a 3.55 Jeep Cherokee.  

I asked this question over 4 years ago here is a link to that thread. 

 

[Plymouthy Adams]

as a bit of foreword on swap...as Andy stated, flange to flange is the key measurement, back to back is to undefined as brakes will alter the back to back on these other axles.   ON swapping, remove your original, place a level on the axle perch, then measure the angle of the pinion, when setting the perches on the donor axle, do this by setting the angle of the pinion to your original removed axle, level the perches at the marked position for spring width and ensure level..tack in place...reverify angle of pinion and perches at level and still on the money, do you welding.  Now you can simply fit the axle without futzing under the body setting or test angles.

Edited January 8, 2020 by Plymouthy Adams

[Booger]

thanks to all. great advice

[Brad47]

I have a Ford 8.8 with 3.55 gears out of a Ford Explorer in my 47 coupe  Fit like a glove 

[Bob Riding]

On 1/8/2020 at 10:21 AM, michaelmarks697@yahoo.com said:

thanks to all. great advice

I am putting a '92 Ford Ranger third member ub=nder my P22 - looks like it will fit with no worries

[Bobb Horn]

20 hours ago, Bob Riding said:

I am putting a '92 Ford Ranger third member ub=nder my P22 - looks like it will fit with no worries

I installed a 95 Ranger rear in my 38 Coupe several years ago.     I had to add spacers, since the Ranger rear was not wide enough for the wheel tire combo I use...

The 3.73 gear makes for very good gears, but I think the 3.55 Jeep rear will do a little better....