Future build questions. stock YJ gearing and 35s. driveshaft length.

MrZucchinihead · 05-25-2009, 01:06 AM

hi, im 17 and have been saving for a while to build my own jeep, and i should finally have enough to dive into it this summer.

a friend of mine's dad has an old cj7 and its him that really got me into wanting a jeep and he said that if i put 35s on stock YJ axles with the stock gearing, they'll eat up the gears, and that id need some tougher axles. now i don't have any problem believing this because he's been a mechanic his entire life, but id like a couple other opinions. would 33s be fine on the stock gearing?

if i have to get new axles for 35s what would be the easiest to swap out? Dana 44's? and does anyone have a ballpark estimate what a local junkyard would charge for one?

another thing im wondering is about lifting it. he said if i go for a 4" lift, i shouldn't need a new drive shaft, the stock length would be fine. anything over that, like a 6" lift that i want, ill need it lengthened or a completely new one. once again i believe him on this too, id just like a second opinion.

and the last thing im wondering is how well would 35s fit with a 4" lift? and if they don't fit good enough would 1-1/4 lift shackles make enough room for them?

thanks a lot, im really looking forward to a nice project over the summer and i just want to be sure on every little detail so i do it right, let me know if there's anything vital id need to know.

levergun · 05-25-2009, 03:57 AM

Hi and welcome. First of he is right. 35's and stock axles and gearing is asking for trouble. The rear axle is a dana 35 and it's famous for breaking. It will also make your jeep powerless, unbelievably slow and not capable of going over 55mph.

What are your Jeeps specs??? What engine, tranny, and gear ratio???

As far as axles go. The front should hold up dcent enough, maybe with a few upgrades. The rear on the other hand, some people break with 31's, others run 35's no sweat. The best axle to swap in are a rear axle from a 91- 01 explorer. It's a 8.8 and very durable. If you get one from a 6cyl. w/ tow package it has 4.10 gears too. Also 95- 01 have year disc brakes which is another upgrade. My axle cost me only $50 at a local you-pull.

As far as tires and lift- 4" of lift is considered the minimum for 35's. There are people who runs 35's with less but they have tons of rubbing. If you do lift shackles the most you can run without rubbing are 31's. With a 4" lift you can usually get by with a t'case drop. A 6" requires a slip yoke eliminator which replaces the output shaft of your transfer case and uses a double cardan driveshaft. Price for the SYE and d-shaft is usually around $500.

dodger889 · 05-25-2009, 06:00 AM

Quote:

Originally Posted by levergun

Hi and welcome. First of he is right. 35's and stock axles and gearing is asking for trouble. The rear axle is a dana 35 and it's famous for breaking. It will also make your jeep powerless, unbelievably slow and not capable of going over 55mph.

What are your Jeeps specs??? What engine, tranny, and gear ratio???

As far as axles go. The front should hold up dcent enough, maybe with a few upgrades. The rear on the other hand, some people break with 31's, others run 35's no sweat. The best axle to swap in are a rear axle from a 91- 01 explorer. It's a 8.8 and very durable. If you get one from a 6cyl. w/ tow package it has 4.10 gears too. Also 95- 01 have year disc brakes which is another upgrade. My axle cost me only $50 at a local you-pull.

As far as tires and lift- 4" of lift is considered the minimum for 35's. There are people who runs 35's with less but they have tons of rubbing. If you do lift shackles the most you can run without rubbing are 31's. With a 4" lift you can usually get by with a t'case drop. A 6" requires a slip yoke eliminator which replaces the output shaft of your transfer case and uses a double cardan driveshaft. Price for the SYE and d-shaft is usually around $500.

You can save a little here is by get a xj front drive shaft and have it re sized for the right length for you just make sure that when you get one that it is in good shape without any play in the cv joint and have it balanced. $40- to 50 for the drive shaft and about $50 -100 for cutting down and balanced. The sye can be between $200 - 275 depends on where you get it.

Pyrate_7 · 05-25-2009, 07:38 AM

Actually, I ran with stock gears and axles for quite a while, and had no issues, other than 5th gear being pretty much useless. I could run 65-70 mph on the highway, but I had to use fourth gear. 5th just didn't have the guts to get it done.

Right now, I'm running 35's with a spring-over-axle conversion front and rear, and 4.10's. I'm in the process of swapping out the D35 for a Ford 8.8 (pretty much a bolt-up swap), and then I'll be painting it and Rhinoing the interior. Here's what it looked like this past winter:

MrZucchinihead · 05-25-2009, 12:46 PM

Quote:

Originally Posted by levergun

What are your Jeeps specs??? What engine, tranny, and gear ratio???

oh, hah, probably should put a question about this too. i dont have one yet, its coming down to a YJ or an XJ, but im 99% sure im gonna spring for the YJ. and im going for a 4L or 4.2L I-6, and 5-spd trans. are there different gears for different years? or does it more depend on where they were manufactured and stuff like that?

Quote:

Originally Posted by levergun

As far as axles go. The front should hold up dcent enough, maybe with a few upgrades. The rear on the other hand, some people break with 31's, others run 35's no sweat. The best axle to swap in are a rear axle from a 91- 01 explorer. It's a 8.8 and very durable. If you get one from a 6cyl. w/ tow package it has 4.10 gears too. Also 95- 01 have year disc brakes which is another upgrade. My axle cost me only $50 at a local you-pull.

would the 8.8 bolt up exactly? if i need to weld a little its not a big deal, that friend of mine's dad said he'd weld a SOA conversion for me if i wanted to go that way. and is the 8.8 the same 5 on 4.5 bolt pattern? or would i need new wheels?

Quote:

Originally Posted by levergun

As far as tires and lift- 4" of lift is considered the minimum for 35's. There are people who runs 35's with less but they have tons of rubbing. If you do lift shackles the most you can run without rubbing are 31's.

i dont think you got what i meant. im saying if i get a 4" lift, and 1-1.4 lift shackles together for a 5-1/4" total lift, should that accommodate 35s without too much restriction off road?

oh, and one more thing. my friends dad also has a one piece fiberglass hood/front end from his cj7, how well would that bolt onto a yj?

machinehead131 · 05-25-2009, 01:10 PM

Quote:

Originally Posted by MrZucchinihead

oh, hah, probably should put a question about this too. i dont have one yet, its coming down to a YJ or an XJ, but im 99% sure im gonna spring for the YJ. and im going for a 4L or 4.2L I-6, and 5-spd trans. are there different gears for different years? or does it more depend on where they were manufactured and stuff like that?

The gears vary between the years a lot. Many 4.0l standards are 3.07s but it can vary. 4cyl standard are all 4.10s there is more info in the FAQ

would the 8.8 bolt up exactly? if i need to weld a little its not a big deal, that friend of mine's dad said he'd weld a SOA conversion for me if i wanted to go that way. and is the 8.8 the same 5 on 4.5 bolt pattern? or would i need new wheels?

To do it correctly the perches need to be cut off and you either need to buy new perches or reweld the new ones on at the correct width and pinion angle.

The 8.8 is 5x4.5 - big reason why the swap is so great

i dont think you got what i meant. im saying if i get a 4" lift, and 1-1.4 lift shackles together for a 5-1/4" total lift, should that accommodate 35s without too much restriction off road?

If you had either tube fenders or TJ flares you may be okay from what I have read. I have 33's on 4 +5/8" lift and it rubs crazy on the back. I would also get a 1" BL

oh, and one more thing. my friends dad also has a one piece fiberglass hood/front end from his cj7, how well would that bolt onto a yj?

Not sure on this.

10characters

MrZucchinihead · 05-25-2009, 05:33 PM

thanks for all the help guys, it's really been a help

if i dont swap out the ford 8.8, could i still use 35's if i got new gearing and internals for the dana 35? or would doing the ford 8.8 and re-gearing the front be that much cheaper?

levergun · 05-25-2009, 06:17 PM

The Ford would be much cheaper and more durable in the long run. You don't even have to regear the front. Just get a front axle from a 4cyl. YJ (5spd. are always 4.10s) and drop it in. I put about 7-8 hrs. into my 8.8 swap and less than $100. In fact I think it was the cheapest upgrade I've done!!!!