Bought a ’92 Ranger - Bad Vibration on the Way Home

[rangerenthiusiast]

Hey, folks.

As the title says, I just bought a 1992 Ranger (4WD, 4.0 Automatic) and while bringing it home, noticed a bad vibration starting at about 45 MPH. I usually take any vehicle out on the highway before buying, but it was raining the day I went to look at her and i just needed to stop shopping for trucks. The guy I bought it from was kind of shifty, so I’m not really all that surprised that there are problems right off the bat. Luckily, I paid 1500 bucks for her, so it’s not a huge hit, but still.

Anyway, my first thought was that maybe it was an unbalanced driveshaft (had this problem on a previous vehicle years ago and it feels similar). Then I thought of other things like a bent rim, bent axle (please god, no), glazed rotors (the brakes were changed just before I bought it), or an unbalanced rim (since one of them seems to be missing any lead weights on the outside).

But then about halfway home, I noticed that the 4x4 light came on and went off a few times, and wasn’t terribly responsive when I pushed the 4x4 button on and off. I also noticed that it seemed like the front wheels might be kicking a little sand when I took off from a stop sign. The truck has that stupid electronic 4 wheel drive with automatic hubs, which I have no experience with at all.

Any thoughts of where to start? Maybe taking it to a tire shop to check the balance on the rims?

Thanks a bunch.

 

[MastuhWaffles]

I would check all the tires for wear or anything odd with them, also check the pressures in them. Probably also rotate the tires too.

If not maybe get an alignment and see if that helps.

 

[KBOI]

Vibration at 45 is a strong indicator of a tire out of balance

 

[rangerenthiusiast]

Vibration at 45 is a strong indicator of a tire out of balance

Thanks, KBOI! I’d be thrilled if it’s something that simple.

In regard to the 4WD, I probably should have mentioned a couple of other things. I have to press the 4WD button again and again to get it to either light up or turn off. Also, the LOW RANGE button does not light up at all when pushed. Finally, the headlights went out for a quick second, then came back on (I read somewhere that there’s a shared ground or something between the headlights and the 4WD buttons). Anyone familiar with this?

 

[racsan]

auto hubs? maybe one didnt unlock, i had that issue once and i think it vibrated, i know there was a strange noise though. never had any problems with my electric shift case, i did go to warn manual hubs, mostly so i could use low range but just have rear wheels powered, for backing trailers and coming up out of a boat ramp.

 

[rangerenthiusiast]

Just a quick update for everyone that was kind enough to chime in on the thread and those that come after.

Turns out that the problem was my fuel injectors. They were absolutely disgusting. After blowing an INCH of rotting, oily pine needles from the top of the engine, I replaced the two air intake gaskets and all six injectors (after a trip to the local parts store for a set of Torx sockets, due to needing a size 7 that my Haynes manual neglected to mention).

It was a frustrating day of cleaning, losing tools, and cursing a lot. But after 67 bucks for a rebuilt set of Bosch injectors, $23 for a set of Torx sockets, and $7 for carb cleaner, I’m up and running with NO MORE VIBRATION. HUZZAH!!!!!