Questions about J mod this week

OchoMarko

Well-Known LVC Member
Joined
Sep 26, 2010
Messages
273
Reaction score
26
Location
Jacksonville (originally from Houston)
Hi everybody,

Sometime this week I am gonna tackle the J mod and would like some tips to make it as smooth as possible. I also have some burning questions because this is such a precision job. In the 98 only Jmod sticky above, are the holes labeled also the same holes for 1995 trannies, albeit with the different notes that applied? Just trying to be 100 percent sure before I start enlarging holes. Thanks for any help in this matter. I already ordered all the necessary parts, ie: pistons, springs, separator plate gaskets (had to go to AAMCO because Ford stealership said they were obsolete). Prices have gone up a lot since the articles in TCCOA came out.
 
when i jmod'd my 93, all the holes did not line up. they were all there, but in a slightly different position than a 98 plate...
 
Thank you Chris, can't wait to do this tomorrow. Hopefully this gov'ment shut down doesn't shut down the auto hobby shop on base or else I'll have to do this on my back in the drive way. The separator gaskets I got from AAMCO are somewhat different than the TCCOA articles picture of the gasket. But the AAMCO guy did order the 93-95 part number, yellow stripe according to his supplier.
 
Well, new plans are afoot. I was reading all the old jmod threads on LOD and found a link to Rob's Tire and Auto. He sells predrilled separator plates and is only 150 miles from me. I told him I have the new 1-2 and 2-3 pistons and separator plate gaskets. He told me, he can send me the 300 hp spec separator plates to me for $45. I thought, this is a no brainer so I ordered the plate from him. The deal is, I just send him my factory separator plates back to him so he has stock to sell. He said it will get here Friday so this is good news.

Here is a link to his services and his web site.
http://www.robstireandauto.com/products.html
 
he was the person DLF sent me to for my plate when I had the 96 trans installed in my 96..
Works like a charm... just go over the drilled out holes with a little emery to clean them up.. debur it and then clean real good.
I left the spring out of the 1-2 shift and left it in for the 2-3 shift. i like the snappy 1-2 when I get on it but under normal driving its more of a positive hit then a slam. some left the sprint in 2-3 out as well. Since im mostly stock, i choose to keep a little comfort in there. can always remove if needed.

Good Luck.
 
Let us know what drill template you use..like you said the 98 jmod instructions are different from a 95 and possibly other years. I'd like to eventually jmod my trans too so this will be usefull info.
 
Rob said he has plates for 95 and newer, I asked him for the 95 plate. I will take lots of pics of both plates and the new and old gaskets too. If he doesn't drill out the number 10 hole for quicker reverse engagement, I'll do that myself. He told me to leave bottom spring in 1-2 which I had planned to do and leave the 2-3 spring out. I work for the post office so I can probably get it at 6am when it comes in from Fayetteville.
 
Is the 95 plate the same as the 94?
We need as much detailed instructions as possible! And plenty of pics too!

I'm watching this thread like a hawk!
 
I have a plate that came out of Dan's 94 and it's already drilled. Still in the box he sent it to me in and I haven't installed it yet. I could take a few pics of it but I don't have another to put beside it for comparison.
 
IMO this is the best way to go
The recal pro
http://www.becontrols.com/aode.htm

I actually installed that kit with my very first 95 Mark Viii, it was pretty much a Jmod with some extra components and springs with incredibly detailed instructions so it made the job easy.

Spree, I believe the 93 to 95 plates were the same, I think they started changing things in 96 and up because Dirty Dog only sells 96 and newer plates. In addition, when I ordered the separator plate gaskets from AAMCO, they had listings for 93-95 and then 96 and up, so something changed, just not sure what.
 
My coworkers told me they got a late shipment in at 1130am, one and a half pallets and two giant cages of parcels. My plates should have come in yesterday but did not, so hopefully they're in those late shipments. I might just stop by and dig in the parcels myself, I wanna get this done! More good news, the auto hobby shop is still open at Camp Lejeune so I'll be doing this on a nice lift.
 
Crap its still not here, wonder if the Post Office lost it. Now I'm thinking I might just go ahead and drill my own plate and sell the predrilled plate once it gets here, whenever that may be. I may just wait til next Sunday to do this or if I'm too impatient I'll just drill my own plate tomorrow.

While going through old threads, I found Driller's post with the Bauman shift kit thorough instructions. His was a 94 so this will apply to 93 to 94 I'm guessing.

Here is the link from the old 2008 thread about Jmodding.

http://imageevent.com/driller/baumannshiftkit
 
Well, on Wednesday October 30, I finally got a day off from work so I finally took my car to the auto hobby shop to do the J mod. I took my sweet time and I have some very important pointers that were never mentioned in any of the write ups on the J mod. I will post descriptions above the pictures for easiest reading and no wall of text.

Tools that you need to make this job as easy as possible are listed here:
good set of snap ring pliers
5 or 6 inch C clamp, the thinner the better, there is not much room to use a larger clamp.
1/4 inch air impact or a nice 19.2 volt impact driver would be ideal
a 1/2 inch drill that can accept 29/64th drill bit, my drill is only a 3/8 and my Harbor Freight bits do not have reduced shanks to fit (the drill is to install a drain plug in the pan, I bought a universal 1/2-20 plug) Ran out of time to install the drain plug
8mm and 10mm sockets and 4 or 6 inch extension
inch pound torque wrench
razor scraper

I will skip the drain pan removal and the easy stuff and get to the meat of the job. Pictures will start right now.

These are the parts set up, gaskets and J mod write up and the drilled separator plate bought from http://www.robstireandauto.com/products.html I only paid $45 shipped because all I needed was the predrilled plate
I have to send back my original undrilled plate. I circled all the holes that needed drilled and made sure they were all drilled out correctly.

Parts_zps347ab819.jpg



Plate with numbers circled to make sure all holes were correctly drilled, I ordered a 1995 300 hp spec sep plate.

pdrilledplate_zpsae886b7a.jpg


Make sure that bracket, the rooster comb and shifter valve are memorized in the proper place so you can put the valve body back without any problems

pvb_zps5f18369e.jpg



This picture shows the four electrical connectors in their proper place but this is really fool proof because the wire harness is perfectly matched so you can't really plug in the wrong connectors. Better safe than sorry, I always say.

pelectric_zps1514b00a.jpg


Another shot of the rooster comb and connectors and shifter valve thing

pvalvebod_zpsc09d94b0.jpg


Valve body removed, notice the 1-2 accumulator piston cover is still intact and so is the 2-3 accumulator piston cover. It is way easier to remove the snap ring holding the 1-2 piston assembly in with the valve body removed.

pvbremoved_zpsefd903b7.jpg


Here is the part that had me stuck for awhile as I tried to figure out why the heck it was so much harder to get the 1-2 piston assy' back into the bore. As you can see, the bore is tapered, so my piston kept getting stuck on the lip up top. In order to install the piston, it has to be installed straight up into the tapered area of the bore or you'll never get the piston assy' installed. I used a 6 inch long 1/2 inch extension with a 22mm socket under the piston and put it into the bore as straight as possible and it went all the way up into its bore. My piston was in good shape and both springs were not broken. The upper spring was orange and the bottom was purple. I replaced both springs with 2 purple ones. Once the piston is in its bore, its easy to install the lower spring and cover. Gently use the C clamp to keep it in its bore while you reinstall the snap ring.

p12bore_zpsdf4ce7f1.jpg


This is the original 1-2 piston and the original springs with a new spring, the other purple spring was on another bench. Notice the old style 2-3 piston in the back ground. Also notice the two 8mm bolts with the bracket and rooster comb wheel in the back ground.

p12acc_zpsae83c747.jpg


This is the new style 2-3 piston next to the original. Notice the 2-3 piston cover in the picture. I did not have to bend any tabs to keep the 2-3 piston in place, the cover had plenty of tightness. I left the lower spring out as suggested by everybody. Don't forget to lube up the new pistons with fresh Mercon V.

p23acc_zps4fa6fe38.jpg


This is the sep plate with holes circled just to make sure it matches up with the TCCOA article pictures. All holes checked out. Number 10 is the larger reverse engagement and it now goes into reverse right away, no lag.

pdrilledplate_zpsae886b7a.jpg


Valve body assembly removed and ready for surgery. Memorize the Pac man shaped discs but I think they only go a certain way. I just laid them out like I took them off to be 100 percent.

pvbg_zpsfa7de239.jpg


Separator plate and Pac Man reinforcement discs removed. This was a pretty gay part of the job, gasket removal. You will need a good razor blade or razor scraper to make life easy. I only had a few areas that were hard to remove but from the valve body. Since I have a new predrilled sep plate, I didn't have to remove the old gasket from the sep plate. I guess Rob will have to do that when I send in my sep plate. Make sure none of the old gasket has fallen into the little mazes in the valve body. If they do, make sure you pick it out.

pgasket_zps4cf9af83.jpg



This is the new sep plate ready to get bolted onto the valve body. Make sure you use fresh Mercon V to wet the gaskets as you put it onto the separator plates. Next you just have to reinstall the Pac Man discs and torque everything to 92 inch pounds.
DON'T FORGET the single 10mm bolt that helps secure the sep plate to the valve body. I kept the valve body up the whole time to prevent screens and check balls from falling out. The fluid inside was pretty fresh so I didn't really have to clean the valve body.

pplateinstalled_zpsa1f643d9.jpg


Finally, when you're ready to reinstall the valve body, make sure you grab one of the longer 8mm bolts that goes into the reinforcement plate on the valve body. The outer perimeter of the valve body uses slightly shorter bolts because of the plate. Line up the valve body and start the bolt into one of the center bolt holes so that you do not have to keep holding up the valve body. Make sure the shifter valve spool thing is in the proper position as you install this first bolt. Hand tight it so that its mostly tightened and then you can hand tighten the rest of the 8mm bolts all around the valve body. Once all bolts are hand tightened, use the tightening sequence picture in the TCCOA article and tighten them all down to 92 inch pounds. Don't forget where the one bracket and the one bolt holding the rooster wheel goes. You will see this clearly as you're doing it, its hard to explain. Make sure all bolts are accounted for, install a new trans filter, making sure the old O ring isn't in the hole. Mine was still in so I just pulled it out with a pick, be gentle and don't nick the soft aluminum. Don't forget to reinstall the 4 electrical connectors. Put the pan back on and tighten the 10mm bolts.

Because I spent 4.5 hours doing this, most of my old fluid drained out. I had to put in 8 or 9 quarts to get the level to right in the middle of the cross hatches on the hot part of the dip stick.

Test drive and enjoy your hard work. The shifts are definitely quicker and smoother but not too firm. When I did the Bauman shift kit in my first 95 Mark Viii, I had to change out some valves and springs and did my own plate drilling. That tranny shifted way firmer and harder than this J mod. I'm thinking of removing the lower 1-2 piston spring to see how I like it. I ran out of time so I didn't get to install my drain plug. I'll have to drop the pan soon to do this mod and may or may not remove the lower spring. It's a lot more responsive and I'm sure my gas mileage will get much better due to the quicker shifts.


Hope this write up will help people in the future. Here is a shot of my car in my front yard.

side_zpsd46da519.jpg
 
Last edited:
Cool. I just did the Jmod on my car today. I removed the 1-2 spring and left the 2-3 spring in. I shifts much better.
 

Members online

Back
Top