4Low question...

[GaryMB]

RE: Re: RE: Pictures

I never imagined i would still be asking a newbie question this far into owning my jeep, here I go: is there a recommended max speed for 4 low? A friend of mine has a grand cherokee and seems to think that he cannot go past 2nd gear in 4low w/o damaging the transfer case...I'm wondering if anything like this applies to my cj7 with the dana 300.

 

[88Wrangles]

Re: North and South

It's usually something like 55, but most people never go that fast.

When you get up into your highest gear, just don't go any faster when the engine RPM's start getting too high.

 

[mud4feet]

It's usually something like 55, but most people never go that fast.........

I can't even begin to imagine going that fast in 4Lo (or the reason for it)! :shock: If you get 'er going 20, you should probably be in 4hi.

 

[88Wrangles]

ya, but most vehicle's manuals say 55....which is why I also made the comment about going by the engine sound--just like how you know when to shift.

 

[mud4feet]

I don't think my 4banger could make it to 55 in 4lo! Barely makes it (uphill) in 2wd! Can't even imagine what it'd be tachin' at 55 in 4lo (probably 0 - blown engine!)

 

[TwistedCU]

She'd be screaming at 55 :shock:

4Lo isn't for speed. I'm sur your buddy would be fine in any gear, so long as he's not winding it out. Common sense rule applies here. "top" speed for 4lo would differ greatly depending on gearing, tire size, transmission but I sure would hate to find the top end the hard way... it's made for pulling and crawling not for flying.

 

[88Wrangles]

RE: Sig question

Hey, I was just going by what most manufacturers reccommend. Wether the vehicle can go that fast or not is another story. It's just like how some axle assemblies (like 'Mog's, Rockwells, etc) have speed ratings on them. It's mostly to keep too much heat from building up.

Another words, he'll be fine using common sense like TwistedCopper said.

 

[mud4feet]

RE: Sig question

Common sense RULES!!!!!

 

[jay79cj7]

I am certain that the recommendation for 55 mph is for 4hi, not 4lo.

 

[TwistedCU]

New Jeep owner's manuals (TJ's) say 55 mph is the fastest speed at which you should shift into or out of 4HI

 

[Junkpile]

There are no limiting factors to how fast you should be able to spin it other than engine rpm. I assume the iron, gear driven cases could handle it better. Heat buildup is a problem.

I forget the actual numbers now, but my 79 CJ5 should have been able to reach about 95mph in low range with the transmission in 1:1 gear and the engine spinning 5,800 rpm.....I think. It was a "spare parts Jeep" that had 3.54:1 diff gears, 2:1 low range, and 39" tires. It stayed locked in low-range all the time and never saw anything but mud.

 

[graewulf]

RE: Re: RE: 4Low question...

If you get 'er going 20, you should probably be in 4hi.

I second that... I regularly leave my transmission in OD(auto) when in 4lo on the trail. You won't damage the T-case on the short distances that you run in 4lo on the trail. In my mazda (stick) I used to leave it in 4lo and run 2nd or 3rd gear on the trail, usually keeping it under 20mph

 

[Bounty__Hunter]

Humor and other things

The 55mph mention has always been for switching between 2hi and 4hi, from everything I've seen.

You can run higher gears than 2nd when in 4lo with no adverse effects.

 

[88Wrangles]

The 55mph mention has always been for switching between 2hi and 4hi, from everything I've seen.

You can run higher gears than 2nd when in 4lo with no adverse effects.

Ya, that is true. But SOME (I don't know about CJ's though) do reccomend that you stay under a certain speed when you are in low range. Either way, it's faster than most would ever want to go in 4lo.

 

[GaryMB]

RE: 1979 jeep cj question

Good to know; I just wanted to make sure...sometimes at Hollister I'll cruise from trail to trail in 4lo, 4th or 5th gear to save the hassle of shifting the transfer case...maybe I'll start going into 2hi instead and practice swinging that locker around.