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View Full Version : 4R70W Lost 2nd gear and Overdrive...Need advice!!!



HookedOnCV
06-14-2005, 09:49 PM
First off as many of you may know, I have a 2001 Crown Vic with an AED s/c making around 310 RWHP. Stock 11.25" TC, J-Mod'ded transmission.

I ran up from around 5MPH under WOT, but when the 1-2 shift was supposed to occur it doesn't. No loud noises or anything...it just didn't shift. RPM's were around 5500 (48 MPH). It stayed there for about 1 1/2 seconds before I let up on the throttle. I didn't hit the rev limiter. Traction control was off, but I didn't have the O/D cancelled.

I appear to have lost Reverse gear, 2nd gear and OverDrive. I can start out with the gear selected in "2", but it is in 1st gear, and won't shift into 2nd or 3rd. I can run the RPM up to 4500+ (35+ MPH) and back off the throttle and get no engine braking - it is just free-wheeling like I'm in neutral. Above 30 MPH, I can rev it all the way to the rev limiter with no shifting or grabbing torque.

I also tried downshifting from 3rd into 2nd manually, and it just free-wheeled again. Above 30 MPH (3rd gear low TP shift MPH) it is not holding ANY torque in second gear. Same free-wheeling effect when I am in 3rd and hit the O/D button to get it to shift into 4th. No torque holding in 3rd with the O/D on above 42 MPH. If I cancel the O/D, then it will grab in 3rd gear again.

I researched the Transmission 101 article by Jerry at TCCoA again, and did check the shift solenoids resistance which were within normal range. It would appear from reading the article that the intermediate clutch or mechanical diode has failed. I can't distinguish in the article between the mechanical diode and the intermediate one-way clutch. Given the correct electrical resistance of the 1st shift solenoid, I don't believe it is that.

I haven't been into the transmission for about 18 months (22,000 miles). From the dipstick the trans fluid is still bright red. No indication of burning or of any particles (Amsoil ATF used).

Any ideas as to what the probable failure is would be appreciated. I would also like any suggestions as to what other things should be changed when the transmission is pulled for the repairs.

I have a new Marauder TC rebuilt by DirtyD0g, along with the spiral lock snap ring replacement in my possession. I was waiting for a good time to get them installed, but I would rather not have been pressured into it this way.

Thanks for your input folks!!!

Todd

sfsv
06-15-2005, 02:40 AM
:cool: I will ask my shop foreman about this today. I had this same problem with a stock GM a couple months ago.

mrjones
06-15-2005, 08:08 AM
This isn't helping your problem, but a long time ago I had an 86 Ranger V6/auto. The transmission went out in it at 205K. My transmission guy said that it was going into 2nd and reverse at the same time. It was sort of fun. You'd take off in Drive/first gear just fine, when it shifted into 2nd, the trans/rear wheels would lock up and you'd slide along for 10ft or so. Best truck I ever owned.

RoyLPita
06-15-2005, 08:41 AM
According to the trans tech at my workplace, the shell broke (base part #7A019). I couldn't say if just replacing that part would help you out.

SergntMac
06-15-2005, 08:54 AM
No matter what our opinions here may be on what's broke, that tranny is coming out for repairs. IMHO, everything you'll need is probably in Reinhart's Stage II kit, once you get a proper diagnosis and start the rebuild, use as many parts from this kit as you can. Do it right the first time, won't have to do it again. Good luck!