How fast in 4WD High with no REAR driveshaft

Im curious, how fast can one go without a rear driveshaft with only front wheel drive on 4HI. I kept it under 55 seems fine.

 

6 mph tops, you go 7mph plus and your tranny will grenade.

 

Uh no... Drove my 2005 Tacoma 55mph for a month on 4HI with no rear driveshaft.

 

He thinks he's making jokes.
They aren't funny and just make him sound stupid.

In any case, I'm not sure if you really mean "can", or if you actually mean "should".
CAN: it CAN go just as fast in FWD as in RWD.
SHOULD: it CAN go just as fast in FWD as in RWD.
(pay attention: I didn't actually answer the "should" question.)

 

Right but, the front diff are strong, no slip yoke on the front drive shaft. It's likely it could go faster than the 65 limit per interpretation of the manual. My RPM's were all normal, and didn't have any hiccups driving without a rear drive shaft.

 

That 55-65 mph limit really only applies to shifting into 4HI, not necessarily how fast you can go after already being in 4HI

That said, I would think if you're in 4WD, conditions are such that you shouldn't really even be going more than ~60...

Matt

 

I woudn't think the issue of speed would be with your front diff. I think the issue is going to be buring up your transfer case if you try to push it too hard to achieve really high speeds.

 

hp / torque needed for cruising freeway speeds is minimal compared to the loads the diff will see off road.

OP you should be fine to drive at just about any normal speed necessary in a FWD mode. I did it for a bit while doing some work on my rear shaft without issue for a weekend. Now i wouldnt make it a full time or very long distance thing but yeah you are fine to cruise at speed.

Now id make sure to shift the transfer into 4hi while the trans is in park, you dont want to spin the trans up (even in neutral it will spin the output slightly just due to internal friction) and have the transfer case slam into gear. Shift to 4hi in park, then if the tcase isnt going in, shift the truck into reverse or drive and it will spin it enough to clunk in.

 

You can go as fast as you want at your own risk. The front half of the drivetrain is not designed to carry the full load of the truck. I’d be taking it easy no hauling/towing/ hard acceleration.

 

110

 

It make sense that the front diff can handle normal highway speed without issue since 65 and lower is the max mph for engaging the 4 high. Sweet thanks y'all.

 

I'll bite, WTF happened to the rear driveshaft?

 

The previous Drive Shaft had issues. Vibration, knocking, moving away from the spline. I had a billet aluminum CB, had crazy vibration at 58 mph and above. I got a new drive shaft built with a double cardan behind the Carrier Bearing to double my angles.

 

If you have a open front diff... It shouldn't be a problem doing the speed limit!
I've driven like this after busting my rear drive shaft on a trail. Over 100 miles to home.

 

Why oh why in the hell would anyone do this or want to do this???? I could see doing so for a short distance if the rear driveshaft broke or was disconnected but no way would I do it daily or on a regular basis. If the drive shaft needed replacement I’d sideline the truck until I could get it replaced. There’s potential for damage here.
I may be wrong but after a certain speed doesn’t it electronically disconnect the 4wd and thus the front transfer case?
I still don’t get why anyone would do this other than temporarily in an emergency.

 

what lol, ive been up to 90mph in 4wd, why would it automatically disengage its not a chevy

 

You are wrong.