TCCoA Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
1,113 Posts
Discussion Starter #1
Hi all, just needs some feedback before I dive into this repair.

I got the 3.8l engine running where it no longer hesitates at take off, but that opened up a bigger problem. The transmission.

Symptoms:
1. Slow take off, loss of power after the car warms up to regular temp. When first started, it has good take off and shifts well.
2. Hard shifts, 1-2 and 2-3. The shifts are worse when the car has been driven for a while. I replaced the accumulator springs for both 1-2, 2-3 8 years ago but did not do a j-mod or shift kit.
3. Clunking when putting shifter into reverse. This has been going on for some time, and I have a rebuilt drive shaft and well taken care of trans axle.
4. Has trouble downshifting. When I come to a stop and take off, it is dragging until I press on gas peddle and it downshifts and has more power. This would indicate it is not downshifting properly.

From the research I did, the problem points to the valve body.

I was planning on doing a j-mod rebuild on the tranny, but wanted some feedback if I may be looking at more problems. I do NOT want to be dropping the tranny and doing a full rebuild but a valve body rebuild is within my means of resources.

Thanks for any feedback!
 

·
Super Moderator
Joined
·
12,083 Posts
Have you checked the trans fluid? Has it been chanced since you did the accumulator springs eight years ago?

What year is the car? How many miles are on it?

Start with the J-mod, a fresh trans filter and fresh trans fluid. Source and install a newer trans valve body while you're at it (I forget which years are better but I'm sure someone will chime in and tell ya) - I'm running a 2004 Mustang Valve body in mine. If you're lucky that'll fix the problem. If not, well, you're looking at replacing or rebuilding the trans. That's just the nature of these cars at this age.
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #3
Have you checked the trans fluid? Has it been chanced since you did the accumulator springs eight years ago?

What year is the car? How many miles are on it?

Start with the J-mod, a fresh trans filter and fresh trans fluid. Source and install a newer trans valve body while you're at it (I forget which years are better but I'm sure someone will chime in and tell ya) - I'm running a 2004 Mustang Valve body in mine. If you're lucky that'll fix the problem. If not, well, you're looking at replacing or rebuilding the trans. That's just the nature of these cars at this age.
Hey Trunk Monkey, thanks for chiming in. It's a 1994, worst year from what I heard. Only has 148k. The first thing I did was check the fluid and it was smooth, clear and pink. Otherwise, I would have suspected burnt bands or worse.

So, a 2004 valve body worked in yours? Hmm... I was reading some articles about using newer versions of valve bodies in the older trannies. This crap gets confusing after a while, hence the post.

Next big question is where to get a valve body kit? I used Baumann Electronic Controls, LLC valve body J-Mod on my 88 Mark and was not impressed with the instructions for their VB plan. But once it was in, it worked well. I am not looking for performance, so the original VB is fine with me. If I wanted performance, I would rather drop a v8 and better tranny in this car.

THANKS for the input TM.
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #4
I have done some searching for either a valve body / shift kit or a refurbished replacement valve body. All of these are roughly the same prices depending on what I replace.

B&M has a shift improver kit. - Less than $100
Transgo has a valve body rebuild kit - $100
eBay vendors have rebuilt valve bodies from $150
Internet vendors have whole valve bodies from $200 - $400

I don't mind rebuilding the VB, but it sounds nice to just pull the old VB and replace it with a new one.

The kits seem to be based more on tranny mods for performance and do not outline an outright repair of a failing VB.

The more I dug into this, the more it seems combining a shift kit with a VB kit and add a few OEM parts is the best way to do it right.

Pretty confusing when you don't have all the facts about the kits, what they contain and what they will do for the transmission.
 

·
Super Moderator
Joined
·
12,083 Posts
Shift kits are junk. The ONLY mod you want to do on a 4R70 is the J-mod.

RobertP may be able to help you out with a newer VB and he can certainly help you out with everything you need to Jmod. You can reach him at his shop at (910) 947-7044 to discuss details. He'll be in Charlotte on Tuesday but should be available at his shop the rest of the week.

Correction: Mine's a 2003 not 2004 anyway, the reason I have a 2003 Mustang VB is I bought a 2003 Mustang 4R75W transmission that was then built to handle the HP my engine makes. Ford Revised the 4R70W in 2003.

https://en.wikipedia.org/wiki/Ford_AOD_transmission#4R75W


You'll need new valve body gaskets too of course. It sounds like you're comfortable doing the work yourself. Best wishes! Keep us posted as to how it goes.
 

·
Super Moderator
Joined
·
10,666 Posts
Since the V6 has the SBF pattern, I think mustangs are your only late model donor cars. Seems like RalphP and I discussed this last week...

The latest one we can use with our VSS is a 2003, and only some of those; some do not have the tailshaft gear for our VSS.

A 94 EEC needs the same TCC and possibly other VB solenoids as the originals, new ones and a new wire type connector can be had from PATC.

The biggest problem with a used one is the seals, at this age; any of them will need a rebuild now.
 

·
Registered
Joined
·
1,916 Posts
The M5R2 fits the V6 pretty nicely since it's a SBF bolt pattern. :wink2:
Friend of mine in Dallas, TX has an early V6 Thunderbird with an M5R2 in it, with the 3.27 gears, it really wakes the car up! Seat of the pants feel it's got great power, gets it moving well.
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #9
Excellent advice fella's, thank you very much. I will see if I can get a hold of Robert.

I had read the same info about shift kits, basically a waste of time. And for what I am facing, a VB rebuild is in order.

I have several articles on VB work, including Anthony Frusco's article on TCCoA. The more knowledge you have going into a project makes the work easier, imo.

I will keep in touch with my progress and write something up on my progress to help others that may face this.

M5R2? Will have to look into that, thanks!
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #10
I don't think the wife would be happy having to manually shift a M5R2 tranny... :facepalm:
 

·
Super Moderator
Joined
·
12,083 Posts
Never a better time to teach her the joys of driving a manual ... :D
 

·
Super Moderator
Joined
·
10,666 Posts
Never a better time to teach her the joys of driving a manual ... :D
And the best part is, no one can carjack you! :grin2:

(Thugs apparently can't drive stick, from the vids on the internet...)
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #13
And the best part is, no one can carjack you! :grin2:

(Thugs apparently can't drive stick, from the vids on the internet...)
U guyrs r funny!

My wife's first car and the car she learned to drive was a shift. Last shift she ever had too. But she had the car for 17 years and still talks about it. It was a Dodge Challenger made by Mitsubishi.
 

Attachments

·
Registered
Joined
·
58 Posts
Are you aware of TSB-95 that mentions the 1994 4R70W and EEC issue? I've owned two 94's and have had transmissions die in both.

https://www.tccoa.com/articles/mn12-techinfo/tsb/tsb-95-8-3.pdf

You might want to see if you're part of this. If you are keeping the same PCM will just bring the problem back to you in the future. I went with a later trans and the 95 PCM and have been good on the LX. There's no PCM change for the SC so I'm stuck with a problem much like you have on the Super Coupe. I've already got a 2002 Mustang trans in the SC but it's slipping from 3rd to OD. However, I swapped my 94 valve body in for convenience. At some point I'm facing a rebuild too.

Good luck
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #15
Are you aware of TSB-95 that mentions the 1994 4R70W and EEC issue? I've owned two 94's and have had transmissions die in both.

https://www.tccoa.com/articles/mn12-techinfo/tsb/tsb-95-8-3.pdf

You might want to see if you're part of this. If you are keeping the same PCM will just bring the problem back to you in the future. I went with a later trans and the 95 PCM and have been good on the LX. There's no PCM change for the SC so I'm stuck with a problem much like you have on the Super Coupe. I've already got a 2002 Mustang trans in the SC but it's slipping from 3rd to OD. However, I swapped my 94 valve body in for convenience. At some point I'm facing a rebuild too.

Good luck
Good morning Scott, thank you for the information, it is VERY useful.

So, when I do the valve body upgrade, I should replace the PCM from a 95 T-Bird or Cougar from the junk yard? That is what I understand from the article. They did mention replacing the Transmission Main Control Assembly...is this necessary?
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #16
Does anyone know what cars / trucks use the same PCM as the 95 T-Bird / Cougar? The junkyard listed a but load of cars with interchangeable parts, but not sure (cause they don't say) if the PCM is the same.

Also, if I understand it correctly, the PCM needs to be for the same engine and transmission as the 95 T-Bird and Cougar, so that leaves out a lot of cars listed.

Any suggestions?

I would hate to get down to the yard and find out all they have is 95 Birds and Cats with 4.6l engines....
 

·
Registered
Joined
·
1,113 Posts
Discussion Starter #17
Conclusion:

Hi all,
I talked to RobertP and his suggestion was to just replace the valve body with one from a 96-98 3.8l tranny.

Car is up on four jacks, now I just need a valve body.

I would like to thank everyone that has contributed to this post, it has been a pleasure.

The search begins...

Thank you and GOOD NIGHT!
(oh wait... that is for stage performers... )
 

·
Registered
Joined
·
3,762 Posts
I have a 4r70w from my 1996 Cougar sitting at my house. I also have the drill bits for the lowest JMOD setting as that is what I have done previously.
 
1 - 20 of 21 Posts
Top