4R70W Transmission

[Dennis Reinhart]

http://www.tccoa.com/articles/tranny/transmission/index.shtml

This the best article out there, on AODE/4R70W , I have one of these built to these exact specifications in my car it dyno'ed 450 RWHP and the one I am doing now will have close to 550 RWHP the key issue in running 4:10's is the rear tail shaft forced lube modification which is easily done with the Transmission still in the car. I will post some nice pictures of this 10 K motor I am just finishing tomorrow for a 1998 LSC.

Dennis




http://pstr-m02.ygpweb.aol.com/data2/00D/2A/57/B2/1E/nvCz2DNRlxVlOz2FpcFyVJThQYxgHR PN0180.jpg

[Jim]

The documentation for the Marauder lists the transmission as a "4R70W+"

Any idea as to what the " + " is? Torque converter? Any beefier/different internals? Or just marketing?

I'm hoping to find out about my trans today, as a diagnosis of my 'spontaneous 4th to 2nd' problem is found....

-Jim

[Dennis Reinhart]

Upgraded gear set for more torque and upgraded torque
converter

[Jim]

Cool, thanks for the info. So this trans SHOULD hold the 300hp without a problem; I'll just assume my transmission issues are some kind of anomoly, rather than symptiomatic...

BTW, here's a video that shows what happens in my Marauder when you attempt to accellerate, very gently... It's at the bottom of This (http://www.pictobot.com/PictoCode/MailLink.asp?Set=380) page.



(Caution, it's 5.5M)

-Jim

[b4z]

Jim,

just looked at the video. Is your trans slipping? Its not accelerating, but the rpms are up in a major way.

By the way what is your rpm at 60 and at 70mph?

[Jim]

It's not slipping, it's jumping from 4th gear to 2nd, then 3rd, then 4th, then back to 2nd. Repeat. No slipping, just the wrong gear!

Pretty annoying, really; especially at 85 MPH, when 2nd gear gets the engine up to about 5600...

I can check the RPM's at various speeds when I get the car back; but at around 70 MPH (the beginning of the video) I see ~ 2100 RPMs...


-Jim

[SSMOKEM]

Hey guys,

I have the feeling that your AOD will wind up with the same problems the Impala's 4L60E does. They're just not built for performance, especially with our heavy cars. Even though some of our guys have been running fairly quick ETs, it's still a minimum of yearly rebuilds to keep them going.

After 2 rebuilds on mine, I gave up and went to the TH400, which I'm guessing is probably close to the Ford C4 tranny. Some of our guys also went to the T56 manual 6 speed.

We found the magic number on the stock 4L60E tranny to be around 400hp and/or 375lb.ft. at the crank before the trannies start crapping out for the majority of people. We also discovered that higher RPM (6200+) and downshifting manually also killed them quickly.

There are some rebuilders that can make them last , but the prices are quite high, upwards of 2000 bucks for the rebuild.

[b4z]

And the Ford tranny is noticeably weaker than the 4L60E.
I have a friend who works in the maintenance department of
police department and he says that the trannies go out in the Crown Vics and the engines go out in the Caprices.

Evidently the Chevy has problems with the long idling that police cars are constanly doing.

I have another friend who runs a home inspection business and they leave their Chevy trucks idling while they type up the report. He puts a new engine in at around 80-120K miles.

The 4L60E's have been known to go out as soon a 70K miles in heavy suburbans. Especially if there is some towing involved.
The heavier they are the quicker they go.

[MarauderMike]

I found these gear ratios posted on another site for the Marauder, anyone have an idea if they are accurate. Based on how my MM runs it would seem the gear shift rpm's would be correct.

Gear ratios

1st : 2.84:1
2nd: 1.55:1
3rd: 1.00:1
4th: 0.70:1
Reverse 2.30:1
Shift points at wide open throttle:
1st to 2nd gear @ 6000RPM
2ns to 3rd gear @6200RPM
3rd to 4th gear speed limited to 120 mph

[MarauderMike]

Well, I found out the answer on my own, numbers are from the FordMedia website. Guess that means they should be legit

[b4z]

.....and the Impala SS has a 3.06 first gear in the tranny, so it already had an advantage over the Marauder.

[b4z]

I read somewhere that the Marauder has a higher stall torque convertor than stock. Does anybody know what the stall speeds of both units are?

Also in daily driving a higher stall speed convertor can actually make the car feel more sluggish. It is only when you are power braking it or
really getting on it that you get an advantage in acceleration.

[NOTSLO_LT4]

most of the higher stall converters in the impalas make them feel lighter along with 3.73 gears. i have a 2900rpm neal chance race torque converter in my LT4 powered SS. i also have 275/40ZR17 tires so my gear ratio is around 3.90's. ive been through 3 trannies in 3 months with my car since i bought it. but this time i had built by a shop that builds bulletproof trannies. http://www.phoenixtrans.com . they make a bunch of their own torque converters and can beef up pretty much anything. my car only runs mid 12's and i know georges car is running in 11's, now he just needs the gear vendors overdrive. SSeeya

nick