Bronco Forum - Full Size Ford Bronco Forum banner
1 - 20 of 37 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
Hi Board,

My new 1990 Full Size Bronco 302 V8 runs great, only problem seems to be when I engage 4X4 the front wheels jerk and wobble when I turn the steering wheel. It's very noticable - probably jerking the tires several inches each way (left and right) when I turn.

Does anyone know what the problem might be?

Thanks, Clint
 

·
Registered
Joined
·
2,785 Posts
Those symptoms are normal on dry pavement. You are not supposed to use 4 wheel drive on dry pavement, especially when turning. The front end will walk away from where you want it to be while in 4wd on dirt roads too. The 4wd system needs slippery roads, like dirt and etc... to operate well.
 

·
Registered
Joined
·
2,785 Posts
I did it too when I first got my 4 wheeler. In 4 Low your tourque almost triples from some 285 ft pounds (302 motor) to like 750 ft pds of tourque. It's an honest mistake, that should not be repeated.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #10 ·
It's a really big boat smart a$$. ;-) Plus, the tires are worn so they were slipping on the wet pavement.

Just so I understand, it is completely normal for the front wheels to wobble back and forth violently when I turn using 4X4 on pavement?

Daves, is the mistake you're saying not to repeat using 4X4 on pavement?

Thanks for the replies guys, Clint
 

·
Try it now!!
Joined
·
9,124 Posts
What kind of boat? Im curious, seriously.

The front wheels will slip, left and right. You can turn the right front wheel independently of the left front (assuming no LS or locker type device) with a regular open front diff like most of stock Broncos have.

The rear wheels will slip, left and right like most Broncos that have open diffs

However, in 4wd they are connected via the t-case. So while left and right wheels will slip, front and rear will not, because there is no mecahnism in the t-case to allow this. In a turn, the front wheels have to move a greater distance than the rear wheels. It forces them to move the same distance as the rear (the rear has more weight/traction so it wont slip).

Now since you're on pavement, the front wheels have a hard time slipping, so there is alot of bucking and jerking as they grab and release the pavement.

Stock, its not a big deal. Put big tires on with even MORE traction, taller gearing with MORE torque, and bigger motors, and you have a recipe for breaking axles/hubs etc. Thats why its not a good idea.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #14 ·
That makes sense...no center differential, so no way for the two axles to rotate at different speeds thus the front binds.

Now that I'm educated on the subject, I guess my next question is how do I know if I caused any damage? I turned on pavement a few times at the boat landing. After pulling my boat out of the water, I circled around the parking area a couple times while still in 4X4. I would say I was traveling at 5-10 MPH and turned at 90degrees three or four times. Probably binding the front wheels a minute or two at most.

Do you think any damage was done? Is there any tell tell signs where I would know I messed something up?

PS it's a 30' Grady White Bimini center console with twin 225 Mercury 4strokes.
 

·
Registered
Joined
·
3,213 Posts
Something would have told you if it broke. Usually comes by way of a loud bang, loss of movement by way of the skinny pedal, or parts found on the ground. All of this followed by aww shit.
 

·
Try it now!!
Joined
·
9,124 Posts
Wow that is a big boat? Verados?

If you damaged something, it would consist of catastrophic damage. Since there are no "wear items" like clutches or seals that would see more force, it would be a metal breaking failure if you damaged something. A hub would grenade, a ujoint would break, an axleshaft would snap...etc.

Its HIGHLY unlikely you damaged the drivetrain in this manner without knowing. Like I said, with a stock truck, the axles, ujoints/hubs etc, are most likely able to stand up to the limited traction the stock tires provide. As you increase tire size, gearing, and power, the forces the drivetrain sees are substantially higher and driving on pavement in 4wd is to be avoided.



Just FYI, its perfectly fine to drive in front wheel drive (hubs locked, in 4wd, with rear driveshaft removed). Since there is no rear driveshaft, there is no torque bias F/R.
 

·
Registered
Joined
·
668 Posts
Is it safe to use a Bronco with the rear driveshaft removed? Im not saying your wrong ive just been thinking about doing it when i do a gear change. A 30' is a decent sized boat, never heard of the maker though. My next boat is going to be at least 36' double deck, I love florida because you can pick one up for 6-12k.
 

·
Premium Member
Joined
·
5,104 Posts
Now that I'm educated on the subject, I guess my next question is how do I know if I caused any damage?
QUOTE]

Yup, you would know.... (see below)

Something would have told you if it broke. Usually comes by way of a loud bang, loss of movement by way of the skinny pedal, or parts found on the ground. All of this followed by aww shit.
If you damaged something, it would consist of catastrophic damage. Its HIGHLY unlikely you damaged the drivetrain in this manner without knowing. Just FYI, its perfectly fine to drive in front wheel drive (hubs locked, in 4wd, with rear driveshaft removed). Since there is no rear driveshaft, there is no torque bias F/R.
I think it becomes obvious when you break something like this. You would probly be saying something like "oh damn, something just broke" :toothless

Is it safe to use a Bronco with the rear driveshaft removed? Im not saying your wrong ive just been thinking about doing it when i do a gear change. A 30' is a decent sized boat, never heard of the maker though. My next boat is going to be at least 36' double deck, I love florida because you can pick one up for 6-12k.
Safe ???. Recommended, probly not. That said, there have been a few guys on the forum who have used front wheel drive to get their broncos around while repairs have been made. I think if you keep your miles to a minimum you should be okay....
 
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top