4.10 rear gear

MercThunder

New member
Hi all, I hope I'm posting in the right place, as I couldn't find a thread dealing specifically with rear gears.

My question is this: by ditching the factory 3.55, and going to a 4.10, is the car going to still be highway-friendly (using stock size tires)? Once all the mods are done, I'd still like to take it on longer trips. I calculated about a 17-18% increase in ratio, so will it now be cruising at a strenuous RPM, or is it just a moderate increase? Hope this isn't a redundant question. Any help is appreciated, thanks in advance.
 
You'll need a tune to run 4.10 and rpm will be around 2500 at 70 mph Highway gas mileage prolly 21 mpg max. Not sure what the km equivalent is
 
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If there isn't a STICKY on the 4:10 gear swap and the results something is very wrong here.
 
Thanks guys, appreciate the help.

I may have missed the sticky, so apologies if I did. I looked, and didn't see it, but may have missed it.
 
I have a brand new set of FR 4.10s - ring and pinion - if you are interested...I think I paid $200 for em...
 
Repeated ONE more time..............

Swapping to 4.10's will result in:

1 - 2 MPG decrease

Engine will turn about 200RPM faster at 60 - 70 MPH

You WILL need a tuner and a tune so your tranny doesn't go nuts and your speedo will read incorrectly

You will be AMAZED by the transformation.

BTW... the Marauder was supposed to have 4.10's from the factory, but the bean counters needed that extra 1 MPG for CAFE.
 
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I'm having 4.10's put in right now, I'll post when I know more about the changes in the car. My Marauder has a cai, tune, rear cats deleted, resonator delete tips, and a few other little mods, but not a power adder.

I'm sure that the other posts are on point based on over a decade of experience with that mod.
 
Past 2500 rpm the gas goes a lot faster. Got 3.73's and at 80mph it spins at 2500 rpm. I was able to get 23 MPG at 80mph with 3.73 - took the MM on many long trips, including cross country. I also have a performance torque converter...
 
If you need a hand with atune, let me know and I would be happy to help.
A BIG + 1 on contacting Marty (Mo's Speed Shop) for a 4:10 tune. He knows Marauders and is a real expert in the field. Many of us got our tunes from him. Highly recommended. :cool:
 
He can mail you a custom tune. He knows what he is doing.

They just remote tuned a supercharged Marauder that is in Germany..Ontario is plenty close to get it without having to go there..Marty and the crew will work with your schedule not just 8:30 to 5:00..
 
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I wasn't aware it could be performed that way...great to know! Marty just got a new customer :)


They just remote tuned a supercharged Marauder that is in Germany..Ontario is plenty close to get it without having to go there..Marty and the crew will work with your schedule not just 8:30 to 5:00..
 
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