I've done some searching and can't find any info on what 3.06 gears are compatible with my E55. I'm sure this has been discussed but can't find it. Any help would be appreciated!
I've been doing Ford rearends for 20 years but new to the whole Mercedes world.

 

The stock 3.06 gears from a Chrystler SRT8 is what I have.

 

And just reflash my tcm and good to go?

 

Yes

 

What are the RPM's at 80MPH? I wouldn't mind a gear swap

 

I forget but I think 120 is like 4,000rpms it will pull hard in 5th too.

 

What year(s) 300c srt8 am I looking for

 

Think they are a 215mm gear size got mine out of a 10 challenger

 

how much is it to reflash your TCU for the new gearing ?
thx

 

You will go slower in the 1/4 but, top end should scream!

 

Why would you go slower in the qtr other than launch/traction control issues?

 

Srt-8 charger, challenger and 300c all use the same 3.06 gears... Gotta b a srt8 tho.. Hemi cars went down to 2.73 or 2.92.. Can't remember off memory.. What's the factory rear gearing in these cars? Just curious...

And better gearing/ taller gear will do exactly the opposite... Cut your top speed down, but will roll through the gears quicker and much effortlessly.. More gear is always better.. TRACTION PROVIDED

 

E55 is 2.65. Hard to believe how hard it pulls those gears

 

Well with all the low end torque and the aggressive tranny gearing..... Naaaaahhhhhh I'm impressed... But the Chrysler 3.06 being a direct swap, should make for a nice little increase in acceleration and I'd bet a good bit difference at the track

 

You can also swap the entire pumpkin from an SL55/E63/SL63, and then you don't need to bother with the labor of opening up the diff case. You can pickup entire salvage diff's off eBay for cheap.

I did that and put in an E63 diff that had the factory LSD. Factory LSD is not quite as good as an aftermarket LSD, but works fantastic since I paid so little for the entire diff and install cost was really cheap.

If you go that route, search and you'll find many threads that list what gears are in the various AMG models.

 

Interesting, didn't know that.

 

That's good stuff right there! These cars didn't come with LSD? That'd b pretty dumb for a car that makes some much power and torque.. The models you listed have better gearing as well?

 

The sl55 and e63 have 2.82 gears. I'm sure other ratios are out there that will work. 2.82 with factory lsd is worth the change for sure

 

I think the gears with the stock converter would be a huge improvement and traction wont be too much of a issue at the track. I may even take my stall out and have it tightened up since I now have these gears. also with the gears I went back to stock shift points no need to rev the hell out of it now.

 

When you added the gears what did this do to the shift points with normal driving. Did it firm up the shifts as well?

 

Gears will not change the shift points or the shift quality. Only the drive ratio is changed.

 

Bumping this old thread. Can I swap in a complete 08 srt8 challenger diff into my 04 e55 or do I need to actually replace the gears and use the oem 55 casing??

 

What does the entire diff from an e63 run? Sounds like an awesome easy mod to gain lsd.

Alex

 

If you are talking specifically about the 1/4 then yes. Many have tried it and nothing really worth talking about.

SRT8 has 3.06 but they have 7 speed. More gears that's the main thing E55 has 5.

With stock gears the E55 screams to the 1/4 closely topping out 3rd gear. for 1/4 I think it's actually perfect. In drag racing you want to scream through the traps at or even past peak hp rpm. That is a fact. If you tighten up the gears it will shift to 4th and by the time you reach 1/4 you wont be at peak rpms. Now a 1/2 roll race I will take the shorter gears and for daily all day long. But, I do not see a huge benefit from shorter gears for 1/4. Probably will go slower and scratch your head.

Sure you can go to a larger diameter tire to compensate and try to keep it in 3rd. But, now you just put a huge honkin tire and adding weight to the rear wheels or even go to smaller diameter tire to try and rev out 4th. But, you are chasing your tail in my opinion.

 

EXACTLY!

If 1/4 mile ET is important, then going to a 3.06 gear probably won't help. That's why I left the 2.65's in when I did my Wavetrac install. Any increased acceleration will be offset by the time it takes to do that 3-4 shift.

If you are after only "seat of the pants" results, then 3.06 would be a good idea. If you want to optimize your 1/8th mile or 1/2 mile ET, then you need to do the math and find the ratio that has you crossing the line at max RPM in whatever gear you would be in.