I have an 89 F150 with 35s on it currently....and the truck has no problem moving them at high speeds or accelerating.

But, I'm looking to jump up to 37s(I have 9" lift so 35s are a little too small for my taste)


Would it be neccessary to do a re-gear so I don't screw up my transmission due to it not being able to move that big of tire?

On my 35s, I have 15" rims.

And the set of 37s I was offered for a good price, also has 15" rims...so the rims are definitely not going up in size.

Thanks for the help guys, it's greatly appreciated.

 

Which engine and transmission? What gears are in it now?

 

if stock gears REGEAR. Regardless on the fact of motor size... Your transmission will last longer if you gear the differentials to the tire size... id say 4.56. (yes i know its an older pushrod motor of sorts and will have plenty of power regardless.)

 

Currently have 4:11 gears, Auburn Pro Series limited slip differentials front and rear, and the 302 V8.

Do you still suggest a 4.56 re-gear?

I apologize for not stating my setup earlier.

 

with a 302 yes i suggest. but if you had the 351 id say you were fine.

 

M5OD-R2, AOD or E4OD? An '89 with a 302 could have any of those.

Adrianspeeder

 

4.88's

 

Str8t you and your 4.88's...

 

Is the 302 modded or stock?

 

It's a fully stock 302.

Now, if I don't regear, would I have transmisson problems in the future?

And, I get molested at the gas pump anyways with this big of a truck, so MPG isn't really an issue for me.

Thanks for the help to everybody in the thread. It's greatly appreciated!

 

whats wrong with that?

DONT FEAR THE GEAR!!!

those 4.10's wont help too much with those heavy 37's.

 

Again - WHICH TRANSMISSION DO YOU HAVE, please?

 

glc regardless on the transmission he needs to re-gear the truck anyway. 4.56's or 4.88's are suggested. personally i would do 4.56's.

 

For 37's I would go to a 4.56 regardless of trans. The clutch on the manual will get eaten up and an auto will go boom pretty quick trying to get those heavy tires moving.

 

35s are already at limits on the stock half ton axles.