80-86 bronco lift kit

[alanauclair]

will i need longer drive shafts if i go with a 6in suspension lift compared to a 4in. or would it be a better idea to go with the 4in suspension and a 2in. body. i just don't care for the looks a body lift. keep in mind this is going to be on a truck that is just a restored daily driver. is their any other things i should think about that i will need that do not come with a rough country lift kit?

 

[89Bronco58]

i have an 89 Bronco with a 6 inch suspension lift and 3 body and run on 38 inch tires, i use front and rear stock driveshafts and have never had a problem, just make sure you keep your pitch blocks in the rear, try to stay away from a lift that use blocks to lift the rear end also. Go for a lift that uses new leaf springs for the rear lift. Upgrading u joints would also be a good idea once lifted, you dont have to do it, but its just for piece of mine, also a tip, include your truck stats in your signature, year, model, enging, all of that, it makes replying to posts easier if we know what your driving >-

 

[86_Bronco]

I have gone through 3 rear driveshafts, i know there are many things i need to change what are my best options?

 

[Broncobill78]

There are a lot of opinions out there, for what it's worth here's mine. I've never had a problem needing to extend my rear shaft with 4" lifts, once I got to 6" lifts it was a *sometimes* sort of thing but I DID burn thru a few of them and once I got a 2" extension welded on the problems disappeared and a 8" forget it, it's a requirement. Some guys here have had no problems at all running 6" with stock shafts and I certainly can't/won't argue with their personal experience but all I can say is that I've run the same 6" lift myself and had problems that went away completely when I lengthened the shaft.

I have gone through 3 rear driveshafts, i know there are many things i need to change what are my best options?

Gosh, where to start with *this* one ? First of all what are you running (lift & tires) ? It might be as simple as needing a couple inches added to the shaft. Is everything else ok ? How are the yokes on the rear-end & Xfer case ? A bad yoke can cause you to throw a shaft and not be obviously broken or worn. How are you driving the truck ? If you're goofing around with it a lot and your suspension is frequently reaching full extension then you may want to invest a few $$$ and a weekend in some limiting straps (good advise for anyone who drives agressivly on the trails). You say you've gone thru 3 shafts, well ok but what is the mode of failure ? Have they all done the same thing or what ? Just what kind of damage are you seeing to them because that's going to give you your best clue as to where you need to start.

 

[86_Bronco]

Sorry its been so long, Im in Iraq and internet was sparce. Not too mention i needed to read up before asking questions. So after reading countless post's on this forum i may be able to explain my problem better. As i said i went through 3 "driveshafts" more accurately i went through 3 U joints 2 up near the Tranfer case which also broke the "CV" and the other down at the end by the rear axle. 2 of them happend driving on the freeway (Both long distance trips), and the other during harsh offroading. ok for the specs. 6" suspension and 3 " body lift, 38.5" tires. I am still running the original gears which i now know need to be changed. I love offroading and when i go there is no babying it even if i have to tow it home.

here is what i am thinking and correct me if im wrong

Planning on getting a drivshaft repair kit for Jeff's BG

I read keeping the u-joints greased would help. (which requires taking the whole driveshaft off everytime, correct)

I was told to tilt the rear axle up a bit. (is this a good idea, and would I have to move anything like the shock mounts?)

I went to a local shop to see about a bigger one but the guy wouldnt give me the time of day except to tell me it would cost over $800 and i wasnt even sure what that would involve.

I have read getting one off a Bigger ford truck and making it smaller, what would this involve? cutting, wielding, new end's. balancing. If there is a good post on this, the link would be appreciated because of my internet speed the search function often times out.

I am going to be home soon and then i will have tons of questions and big plans, Thanks

 

[Justshootme84]

To answer the original question, you do not usually need to lenghten the driveshafts for a 6' suspension lift kit. It's always recommended to fully cycle the suspension after the install and check that both front and rear driveshafts have enough spline engagement at full droop. 3 to 4" minimum is my rule of thumb, as you don't want the slipjoint to separate or bind up.

86 bronco, this next part pertains to your problem, too. the rear driveshaft-to-rear pinion yoke angle should be close to zero, about 1-2 degrees below is best. Reason is, when you take off from a start, the rear axle tends to wrap upwards, rotating the pinion upwards in the process. If the anlge is off by more than a couple of degrees, you can get enough binding to snap the u-joint there. When you break one of the u-joints in the CV joint near the t-case, that could be due to lack of grease or normal wear. I've installed many lift kits and when disconnecting the driveshafts, the u-joints are toast, and have been for a long time. Replace them with quality Spicer units, keep them greased, and you should be OK.

My 78 Bronco had a problem with eating u-joints in the rear driveshaft, and the prev. owner finally found the right angle using shims with an add-a-leaf. I installed a 1" zero-rate block under the new, lifted spring pack on my 84 Bronco to correct the pinion angle there. You can get an inexpensive angle finder to check your driveshaft-pinion yoke angles yourself, comes in handy when changing leaf springs or trying out angled shims.

JSM84

 

[Broncobill78]

Hmmm, where to start

I dunno what the driveshaft repair kit consists of but if you've dropped the shaft a few time now I'd maybe consider having a new shaft made and be done with it. A new, custom length shaft should run you somewhere between $400-$600 and should solve most of your problems. A 6" lift seems to run right on the edge of needing a new shaft and being OK, a 4" lift is just fine with stock shafts but at full extension a 6" lift can sometime pull the splines out further than they should go. It's really a judgement call, I've seen guys with 6" use stock shafts for years and be fine and I've also seen them come apart right there on the trail and there's just no rhyme or reason to it as far as I know. I *have* seen small wedges that fit between the spring pad & springs pack that are intended to angle the pinion up a few degrees, don't honestly know how well they work, they're small so the increase in distance shouldn't be so bad as to start the rear-end to loosening the U-bolts but just on principle I hate putting anything between the spring & the pad it's just bad practice. You might also want to consider using something like a Tom Woods "super flex" offset U-joint that will give you an extra 10 degrees, you can find more info on his site http://www.4xshaft.com/index.html A custom shaft will probably take care of the problem but a proper length shaft AND the super-fles U-joint should elimainate any probems with driveshaft angles.

You don't need to remove the driveshaft to grease the U's, what you WILL need is a special needle attachment for your grease gun to get in at the little cup-type grease fittings used in the double cardan joints, you can find info on that type of driveshaft here: http://broncozone.com/forums/index.php?showtopic=12560

Also, be sure the U-joints are in phase when you reinstall the driveshaft, I've seen more than a few fail because this wasn't done. Are your yokes in good shape ? I tore my hair out for months with a 79' that had a bad yoke & kept throwing rear shafts, it's not always the first thing you think to check. I've also seen guys add a *second* CV joint down at the differential and between the two of them they're able to deal with the angles, not that a 6" lift should require something like that but it IS a way to deal with driveline angles.

 

[Hayden Jamison]

I have a 1986 ford bronco with 6inch's of lift and running 35inch tires, it was making this CLACKING NOISE then the back part of the drive shaft fell out, what should i do? get a new Universial Joint or new drive shaft? and if so on the new drive shaft could i use a stock drive shaft?

 

[Bronc76]

If a new U joint is all you need, you should be fine, depending on what condition the rest of the shaft is in. Do you know if you have a stock or custom shaft? You probably should have started a new thread with this question?