hello i have a jeep cherokee it has a vm 35 engine 2.5 td i am going to buy an other cherokee witch is a vm45 2.5 td engine but the turbo is broke i want to know will th vm35 turbo fit the vm 45 engine? thanks

 

I was figuring there would be more pressure due to the smaller contact patch of the narrower tire, so that the tread elements would bite in harder. OTOH, it could just be that the front tires on it now (225/70R15, so 6.5-7" tread) are a hard compound and not a very good tread design for packed snow. What brand and model are your tires?
Also, if I switch to the "XJ standard" 235/75R15s, I'd have to recalibrate the speedo. How difficult/expensive is that?

 

Incorrect, at the same tire pressure, on the same vehicle, tires of similar construction(same model tire, and ply rating) will have the same size tire patch. With a wider tire, the contact patch is wider width wise(side to side) and shorter length wise(front to back) as a tire that is skinnier, but at the same pressure they will both have the same size contact patch.

Wider=better

 

Well, if we compare a shorter, narrower tire (215/75R15) to a taller, wider tire (235/75R15), the latter will have a larger contact patch. Because the vehicle will weigh virtually the same, there will be more pressure on the contact area with the smaller tire. That means it should bite deeper into the snow, but over less area, so the question is whether or not there is an advantage one way or the other; I don't really know for sure.

What brand and model are your tires?

 

hello i have a jeep cherokee it has a vm 35 engine 2.5 td i am going to buy an other cherokee witch is a vm45 2.5 td engine but the turbo is broke i want to know will th vm35 turbo fit the vm 45 engine? thanks

 

The only advantage skinnier tires have in respect to snow traction is in deep snow, where a skinner tire would provide less rolling resistance against the snow in front of the tire. In respect to hard pack, i would assume for the sake of argument that the contact pressure vs contact patch argument will yield approximately the same traction. Tread design/depth is much more important in traction than the tire width.

 

Thanks I will check those bushings agan do you think it could be the bushings in the control arms ?

 

The 215 tires were standard on the base model XJ called the SE. The type that the Post Office used to buy, with the 4 cylinder.

The Sport and up models all came equipped with the 225/75-15 Goodyear Wrangler RT's.


You always want to run a narrower snow tire due to it's smaller contact patch concentrating more weight in a smaller area. Biting into the snow vs riding on top of it as a wider tire will tend to do.

For the same reason with a mud tire you would want the exact opposite in a much wider tire in order to float over the mud vs digging deeper into it.

I've had 215 Blizzaks on my 98 Cherokee since it was new which have performed flawlessly.

I run 235/75 All Terrains (Michelin) the remainder of the year which work pretty good in the snow but due to being wider and the harder AT compound don't bite as well as the narrower Blizzaks do.

I test the tires in the snow by plunging them deep into a turn and see how long it takes before they actually bite and recover.

With the AT's you'd have to plan for a fair amount of drift/understeer or sliding but with the Blizzaks, none at all they just dig right in as if they were on pavement practically.

On dry pavement, wider is better. But for snow, narrower is.

 

My '93 Grand Voyager has 205/70R15s (about 5.5" tread width), and it's hands-down the best vehicle in my family's fleet for getting up our annoyingly steep driveway. My sister's Grand Prix has probably 7" of tread width, and that car sucks at getting up the driveway even with brand new tires.

The other issue is if I were to get 235/75R15s, I really should get four, which is just not in the budget right now. I might actually try to ride the winter out with the tires that are on it right now. I'll feel it out more the next time it snows and make a decision then...

Thanks for all the input.

 

I just installed an overhead console in my 95 Sport and everything works fine except for the compass. It's on, but not accurate. I know there's a trick to reprogramming it, but I can't remember how to do it. I've searched the archives here for 2 days now, but can't find any answers...The owner's manual describes how to do it, but I don't have a copy with this Cherokee (my 6th!). Can anyone hook me up with the "how to", please?

 

COMPASS/DISPLAY SELF-DIAGNOSTIC TEST
This self-diagnostic test is used to determine that
the compass and all of its display segments are operating
properly electrically. Initiate the self-diagnostic
test as follows:
(1) With the ignition switch in the OFF position,
simultaneously press and hold the COMP/TEMP button
and the US/METRIC button.
(2) Turn ignition switch to the ON position.
(3) Continue to hold both buttons until the display
performs a walking segment test. In this test all of
the compass points are displayed, along with various
number combinations. These combinations verify that
all display segments are functional. If any segment
should fail to light during the test, the unit is faulty
and requires replacement. To repeat the test, momentarily
depress and release the COMP/TEMP button
one time.
(4) Momentarily depress and release the US/METRIC
button one time and all segments will light simultaneously
for about 2 seconds. If any segment
should fail to light during the test, the unit is faulty
and requires replacement. To repeat the test, momentarily
depress and release the COMP/TEMP button
one time.
(5) Momentarily depress and release the US/METRIC
button one time or turn the ignition switch to
OFF to exit the self-diagnostic mode and return to
normal operation.
If the compass functions, but accuracy is suspect,
it may be necessary to perform a variation
adjustment. This procedure allows the unit to
accommodate variations in the earth’s magnetic
field strength based on geographic location.
See Compass Variation Adjustment, in this
group.
If the compass display has blanked out and
only CAL appears, demagnetizing may be necessary
to remove excessive residual magnetic
fields from the vehicle. See Compass Demagnetizing,
in this group.

 

Wow, great write up, I hope you copied and pasted it! My wife wonders why we don't have anything better to do on Christmas than talk about Cherokees...I ran the diagnostic checks and everything checks out fine, so I think I need to do the Compass Variation Adjustment and now it reads CAL in little letters next to the N-E-S-W letters, so I'm guessing I need to Demagnitize too...Any text on those parts?...Great help, thanks!

 

It was copied from the FSM. If there's anything else you need, let me know! Merry XJ-Mas!

 

What is FSM? I've seen it alot, but don't have a clue what it means...Would it have something on the Compass Variation Adjustment or the Demagnatizing parts?

 

Factory service manual.