Shift Solenoids - Mac

[MAC]

My trans just started acting up this morning and all codes (P029, P086 & P094) say it's time to replace the shift solenoids. I only have 2nd gear.

P029 (E029) Transaxle Shift 'B' solenoid problem (1st, 3rd, 4th gear)

P086 (E086) Undefined Gear Ratio (Transmission Pressure Control)

P094 (E094) Transaxle Shift "A" Solenoid Problem (Vehicle Speed Sensor)

From what I remember, it's an easy job to replace them. Though I wish I had more of a warning because I want to buy ACDelco but I would have to order them unless I can get them tomorrow from Cadillac for the premium price.

[Bruce Nunnally]

Sorry your Cadillac is misbehaving, but sounds like you have the right plan.

Ray's speed sensor write-up shows the shift solenoids in passing.

[Bruce Nunnally]

Information - heavy thread here.

4T-80E Shift Solenoid Replacment

a) the job is a mess, be prepared.

drop the pan, and careful removing the tranny gasket, it is re-usable. Once you clean the pan, you can reset it with gasket sealer.

c) disconnect the solenoid electrical connectors and the mechanical linkage. The linkage has a metal clip you lift and slide.

d) remove the valve body screws, and drop the valve body.

e) place the valve body where you can afford a mess, it will continually leak. Best thing is to set it on cardboard on a bench. There is a valve spool that can be removed as well, careful it can slip out, you don't want to damage it.

f) remove the two clips holding the solenoids, careful they are spring-loaded and will fly

g) remove the screws holding the "large" portion of the valve body split, this is where the solenoids are incased. Remember the screw locations, there are about four different screw lengths

h) CAREFULLY remove split, there are 4 steel check balls loose inside the split (about 1/4" diameter, they will fly, as well)

i) inspect spacer plate, if the black coating is not chipping off you can re-use it, otherwise plan on spending another $ 70 at the dealership parts house. If you replace it you will have to remove the "smaller" split, as well. It also has three check balls.

j) replace the solenoids

k) now comes the fun,....you will note three holes in the spacer plate where three of the check balls reside, seat them there (appr. 3/16" diameter with a smaller relief hole next to it, as I remember). The fourth check ball will need to be inserted in a spherically-cast cavity, which is near one of the solenoids. You can set it with grease, I re-assembled successfully without using grease.

l) re-assemble valve body, carefully and equally torque.

m) you will note a square black plastic item near one of the solenoids, on the end. Replace this plastic filter with the new filter in the solenoid kit. The kit will also come with an L-shaped bracket that is to be used to "capture" this filter and keep it from backing out. The kit also comes with a slightly longer screw used to mount the bracket to the valve body (discard the old screw).

m) re-assemble valve body to transmission, hook up linkage and electrical connectors

n) replace both tranny filters

o) replenish fluid

p) reset codes

I am told there is a hidden drain plug for the side cover fluid (where most of the fluid is...) that is accessible once the lower pan is removed. The plug is pretty evident on the end of the trans under the side cover. Use this to drain additional fluid out.

[BodybyFisher]

You are taking this in stride MAC, very cool.

I have some photos of the lower control valve assembly, I personally think the hardest part will be getting the check balls back in place.

I have scans of where the balls go, posted, if you need them let me know.

You can now replace the filters, drain the side pan, and replace the pan seal...

Great info Bruce

[MAC]

You are taking this in stride MAC, very cool.

I have some photos of the lower control valve assembly, I personally think the hardest part will be getting the check balls back in place.

I have scans of where the balls go, posted, if you need them let me know.

You can now replace the filters, drain the side pan, and replace the pan seal...

Great info Bruce

I was able to buy the kit at Cadillac for $93 (which includes tax). I wish it was less but I jumped all over it because I certainly don't have time to shop around. The production date is 9/07, so I'm sure it's the latest kit. If you have a photo of the check balls I would appreciate it if you would post it. I know the check balls can be a pain from what I have read. But I also read that grease can be used to keep them in place. If this is the case then hopefully I won't run into any complications.

[JimD]

I can't locate my diagram of the check valve locations (sorry). Someone here will post it.

I would avoid using 'grease' to hold the balls in position; a thin coat of Vaseline works very well for me.

[Bruce Nunnally]

check the checkball graphic BBF posted here.

Install the checkballs (5, 7, 8, 9) into the lower control valve body (903). Retain the checkballs in position with Transjel™.

[BodybyFisher]

Thanks Bruce!

Here is another view of the check balls from an aftermarket tech manual

[MAC]

Thank you Bruce and BBF for the diagrams and the replacement procedure. One thing I still need to do is buy a new trans filter. Advance Auto Parts sells it for about $28 but it's made by Pro-King, which I never heard of until today. They have been in business making trans parts for 40 years so they have a track record. Some Internet research doesn't reveal anything bad about their parts. Since I have to replace the filter I think I'll try the Pro-King. I believe PepBoys sells Fram trans filters.

[KHE]

MAC,

Make sure to use a new pan gasket from GM. None of the aftermarket kits have the correct gasket (that has the steel bushings at each bolt hole). They always include a cleap cork gasket which will result in distortion of the pan holes if the factory torque spec. is used.

The kit from GM includes the gasket and screens and is suprisingly cheaper than just purchasing the pan gasket by itself...

[MAC]

MAC,

Make sure to use a new pan gasket from GM. None of the aftermarket kits have the correct gasket (that has the steel bushings at each bolt hole). They always include a cleap cork gasket which will result in distortion of the pan holes if the factory torque spec. is used.

The kit from GM includes the gasket and screens and is suprisingly cheaper than just purchasing the pan gasket by itself...

I purchased the Pro-King filter and gasket kit since I don't have time to wait. It's raining today so the job will be done tomorrow since it's going to be sunny and 50+. The kit came with a rubber gasket but no bushings. I think I'll go to Home Depot to see if they have anything. Otherwise, I will use the OEM gasket but if it leaks I'll buy an ACDelco. I have everything I need at this point, I'm just waiting for the weather.

[KHE]

MAC,

Make sure to use a new pan gasket from GM. None of the aftermarket kits have the correct gasket (that has the steel bushings at each bolt hole). They always include a cleap cork gasket which will result in distortion of the pan holes if the factory torque spec. is used.

The kit from GM includes the gasket and screens and is suprisingly cheaper than just purchasing the pan gasket by itself...

I purchased the Pro-King filter and gasket kit since I don't have time to wait. It's raining today so the job will be done tomorrow since it's going to be sunny and 50+. The kit came with a rubber gasket but no bushings. I think I'll go to Home Depot to see if they have anything. Otherwise, I will use the OEM gasket but if it leaks I'll buy an ACDelco. I have everything I need at this point, I'm just waiting for the weather.

I would only use the gasket from GM - it is made of a material that swells in the presence of trans fluid to assure that there are no leaks. Rubber, cork or other gaskets without the steel spacers will either distort the pan or will leak. I cannot understand why the aftermarket suppliers can't understand that????

[MAC]

I would only use the gasket from GM - it is made of a material that swells in the presence of trans fluid to assure that there are no leaks. Rubber, cork or other gaskets without the steel spacers will either distort the pan or will leak. I cannot understand why the aftermarket suppliers can't understand that????

I did reuse the OEM gasket which had the steel spacers. It's actually considered a reusable gasket according to the note that was inserted in the kit I purchased. The rubber gasket I threw out. If I need to replace it in the future I will definitely buy OEM.

I replaced both Shift Solenoids and everything seems to be working except that I'm did get the P086 code at the beginning. I replaced 2 gallons of fluid so it might be that there is air circulating that needs to be purged? I then went on some back roads and did some brisk acceleration and manually shifted to work the trans to see if it would eliminate the P086. Afterward I didn't see the code anymore but I won't be totally satisfied until I drive it at while to see if it comes back.

P086 (E086) Undefined Gear Ratio (Transmission Pressure Control)

The job was not difficult. Here are a few tips to keep in mind.

1. had the trans fluid pump out according to the Guru's suggestion by simply removing the upper radiator cooler line and attaching an adapter with clear hose then placing it in a 4 gallon bucket. I turned the engine on and watched the fluid pump out. When it was starting to spit I turned off the engine then reconnected the cooler line. I also got another quart of fluid when I removed the Valve Body. Keeping something under the trans is a must.

2. All pan bolts are the same length so don't hesitate to pull them right out because you don't have to worry about different length bolts. If they are strategically removed, such as loosening them on the opposite side that the car is jacked up on, then loosen the rest, the fluid will flow out of low end first. This way you don't have to worry about fluid coming out from everywhere. When the Valve Body is removed, more fluid will flow. Torque pan bolts to no more than 10-12 N*m (Newton meter) or 8.85 lb. ft. If maximum factory torque specs are exceeded pan gasket and case damage may result.

3. The bolts that secure the Valve Body inside the trans are also all the same length. Again, no need to worry about marking bolts.

4. However, the bolts that secure the Case Cover (or "Channel Plate" as it's referred to by GM's Factory Service Manual) to the Lower Control Valve Body (See BBF's diagrams herein) are NOT all the same length. But this is not a problem if they are simply loosened and pulled out halfway and then use masking tape to tape the same length bolts together in series and then pull them out. Not only will you know where they go, but also, you will be able to put the same bolts back were they came from.

5. The Accumulator Housing does not need to be removed. The Valve Body can be disassembled without removing it to obtain access to the Shift Solenoids.

6. CHECKBALLS are easy to deal with as long as the Case Cover bolts are removed and then the Valve Body is turned over so that once the Case Cover is removed the Checkballs will not fall out. The Checkballs are located where the clips that secure the Shift Solenoids must be removed. Obviously, it's important that the Valve Body with Cover remain tightly together as the Body is turned. If it should come apart then the Checkballs will fall out.

7. Both Shift Solenoids will pop out because the are under spring pressure. So when removing the clip that secures each not only be careful to not allow it to fly out, but also, hold onto the Shift Solenoids. Solenoid A, which will be the one on your right as you're removing the clip, is under greater spring pressure than Solenoid B. They are easy to replace! Simply (i) remove the clip (ii) take the old one out (iii) insert the new one (there is only one way they can be inserted), and (iv) secure with the same clip.

8. Be very careful when removing the electrical harness for each Solenoid because the securing clip can break. I actually used a fine hacksaw blade to remove the raised plastic part where the clip attaches because I didn't want to overstress the clip by trying to get it over it. There is one more harness that must be carefully removed without cutting or damaging it. It's acceptable to saw the old Solenoids because who cares if they're damaged since they're going to be replaced anyway. I just cleaned the harness connections before attaching them to the new Solenoids to clean off any plastic shavings from the sawing.

9. Reassembly is easy since the bolts are clean and it all fits nicely. Do not over-torque bolts on Case Cover and Lower Control Valve Body--Use only 6-10 lb. ft. (See GM Factory Service Manual, pg. 7A-7B-33). Also, if there is fluid on the bolts it may change torque specs as the Guru stated a number of times. So, use common sense and don't over-torque bolts.

Again, I appreciate all the help!

[BodybyFisher]

Congratulations Mac

[MAC]

Congratulations Mac

Thanks! I took another drive and there are no codes. So it looks like all is well, including no pan leak.