Full Size Spare on Rear OK?

[GeoffK]

Does anyone know if it hurts anything to run a full size spare on the rear axle for any extended period of time? If I understand correctly, the full size spare is the same size as the front tire (235/50-18). If you run two different size tires on the rear will this cause any wear on the limited slip differential? I guess this is much less worse than the silly donut mini spare.

[sailsmen]

It will cause additional wear on the ltd slip. How much additional wear is unknown.

Unless you are always driving perfectly straight you are wearing the ltd slip.

[Marauderjack]

Better than the "Donut" spare but I wouldn't drive it a lot on anything other than the same size on both sides!! :(

Marauderjack :D

[RF Overlord]

I can't find it in my .pdf copy here at work, but I know I read in the hard copy owner's manual about only using the spare on the rear for the absolute minimum time necessary, as it would begin to wear the limited-slip clutches excessively...

[TAF]

From the Popular Mechanics article in '02

CLICKY (http://www.popularmechanics.com/automotive/new_cars_trucks/2002/5/mercury_marauder/index6.phtml)

[duhtroll]

And if you have T/C it will cause havoc with that unless you turn it off.

I uh, read that somewhere. :o
-A

[David Morton]

Some misunderstanding about how limited slip works, is at work here. Lemme see if I can clear it up. BTW, I AM an ASE Certified Master Technician.

If you drive like a grandmother and take off normally the limited slip clutches won't engage, and the differential will act like you're taking a long sweeping turn all of the time. This will cause extra heat but if you get the tire replaced soon enough, don't worry about it.

But if you stab the throttle a lot, drop her down into manual second at 35 mph a lot, and generally drive like Gator McKlusky all over town, you will be causing the limited slip clutches to engage a lot and that will wear them, not to mention the wierd way the car will handle during these maneuvers.

(editing) Note the "clicky" link above says you can damage the differential if you drive more than 50 miles with the spare on. This is standard disclaimer boilerplate. Drive 50 miles all at once at 65 mph and you may damage the unit. The clutches run pretty close to each other even when off and do build up a lot of heat when the spider gears are running all the time, remember we aren't running ATF in the differential! The clutches will get scorched but the real damage is to the gear lube! Cook that stuff and you'll start to lose the bearings. But if you drive 2 miles to work at 35 mph and 2 miles back, it'll take a long time to cook the lube cause your just not getting it very hot.

Everybody up to speed now? Limited slip only engages when enough torque is applied to the carrier. Otherwise, we'd be chirping tires every time we turn the corner, literally.

[RF Overlord]

Thank you, Mr. Morton...that WAS my understanding of how the limited slip would work, but you said it better... :up: :burnout:

[GeoffK]

Drive very conservatively :rolleyes: with a spare tire on the rear?

[David Morton]

You got it.

[04MEMA]

But if you stab the throttle a lot, drop her down into manual second at 35 mph a lot, and generally drive like Gator McKlusky all over town, you will be causing the limited slip clutches to engage a lot and that will wear them, not to mention the wierd way the car will handle during these maneuvers.


Hey, shouldn't that be Parnelli Jones? :cool4:

P.S. PMI (Pardon My Ignorance) Who's Gator? :coolman:

Jeff

[Joe Walsh]

Hey, shouldn't that be Parnelli Jones? :cool4:

P.S. PMI (Pardon My Ignorance) Who's Gator? :coolman:

Jeff

Burt Reynolds driving an early 70s LTD with a "Built" 429 Big Block and a 4 speed.
"White Lightning" if memory serves....

[David Morton]

Hey, shouldn't that be Parnelli Jones? :cool4:

P.S. PMI (Pardon My Ignorance) Who's Gator? :coolman:

JeffYou young pup!

Joe Walsh has it right enough. Gators' brother gets killed by the evil sherrif (Ned Beatty) and the ATF boys spring him out of prison where he's serving a sentence for running moonshine so he can go back and infiltrate the local ring that's run by the sherrif to get the goods on him and bring him to justice. They give him a hot Ford and he drives the pee out of it, tricking the sherrif into driving into the same swamp he drowned his brother in, drowning himself.

I remembered it as being a 428 SCJ with a turbo.
4 speed close ratio 'Toploader' transmission.

Lots of BWAAAAAH---WAAAAAH---WAAAAH

Great movie, "White Lightning". Big hit with the rednecks in 1973. They did a sequel "Gator" in '76. Nobody liked it.

[04MEMA]

I saw part of that flick once - the car was brown wasn't it?

[grzellmer]

I saw part of that flick once - the car was brown wasn't it?

I thought it was blue.

"Ain't Scared of nothin, cepin women and the police!"

[2003DOHC]

I thought it was blue.

"Ain't Scared of nothin, cepin women and the police!"


It was brown.

[Joe Walsh]

It was brown and a buddy of mine recently bought almost that exact car (except with a C6 trans) from a proverbial little old lady who only drove it a few times a week. True Story. Got the car for next to nothing, it looks pretty good, and it runs like stink!!! The car is a total Sleeper but will lay down endless strips of black rubber. 429 cid; 4v carb; C6 auto; 9 inch rear...they don't build sedans like they used to!
:hijack: Sorry... :o