j-mod help....

Hi Sho

Those are the original directions for the complete j-mod..from chapter 1 to the end. You may need to print it out or have a j-mod person do it for you. There is a lot of important info in that tech article and someone who has done it before is the best place to start. You can forget the o/d section as it is likely it will not work when you are done unless it is upside down on a bench when you do it, or you know the trick to do it right.
Max
 
mrzeee said:
Hi Sho

Those are the original directions for the complete j-mod..from chapter 1 to the end. You may need to print it out or have a j-mod person do it for you. There is a lot of important info in that tech article and someone who has done it before is the best place to start. You can forget the o/d section as it is likely it will not work when you are done unless it is upside down on a bench when you do it, or you know the trick to do it right.
Max

Hey Max this is Greg in Houston. What exactly is the J-Mod.
 
The Jmod is a modification to the 4R70W by the guy who invented the thing. J = Jerry. Upgraded clutches, manual diode, bands, opening valve body passages, etc... I believe it makes the trans capable of holding 750 ft/lbs. So it's not really a "shift kit", you're really going to gut the trans and put it back together. It's a pain in the ass if you don't have the right tools or experience.
 
CaptainZilog said:
The Jmod is a modification to the 4R70W by the guy who invented the thing. J = Jerry. Upgraded clutches, manual diode, bands, opening valve body passages, etc... I believe it makes the trans capable of holding 750 ft/lbs. So it's not really a "shift kit", you're really going to gut the trans and put it back together. It's a pain in the ass if you don't have the right tools or experience.

Actually Jerry give you complete instructions on how to build the complete tranny. The "J-mod" per-say is the drilling of specific holes in the valve body and changing the 1-2,2-3 accumulater springs. The only special tools you are going to need are some number drill bits, and a set of GOOD snap-ring pliers.
 
Markviiiedrea said:
glorified home made shift kit pretty much!

Eric


couldnt be ANY more WRONG on that comment.

If you dont know, best not to say anything.

if you, or anyone else needs help with a JMOD, pm me. I have done 4 of them!
:Beer :wrench
 
BlackIceLSC said:
couldnt be ANY more WRONG on that comment.

If you dont know, best not to say anything.

if you, or anyone else needs help with a JMOD, pm me. I have done 4 of them!
:Beer :wrench

like i said shift kit, just a better one than most of them out here . and i do know what it is and i have done one. in fact I'm about to do it again with my new tranny.
 
sho89mtx said:
Ok I read all the instructions, but than it says to learn more about the j-mod, click here and it takes you to a page with tons of topics, which chapter or what exactly is the j-mod from here?:
http://www.tccoa.com/articles/tranny/transmission/index.shtml

All of this when read will inform you of the various levels to upgrade the performance of your transmission. Some of the less technical items also help in achieving a longer transmission life thru replacement of the accumulators that tend to get broken spings and sticking. Transmission coolers are also discussed, as well as modifying the shift harshness (Lack of) via drilling the valve body plates. Most folks consider a J Mod as upgrading the accumulators, drilling the valve body plates, adding a trany cooler, draining the torque convertor, changing the filter, and switching over the Mercon V.
Hope this helps with the Jargon, this is a well written article that will help you even build your tranny to greater capabilities with more intensive work.
 
evillally said:
Need to J-Mod my 98 soon...

It was my understanding that the 98's had the upgraded accum piston from Factory... '98 should not need a j-mod!!!
 
Jamler3 said:
It was my understanding that the 98's had the upgraded accum piston from Factory... '98 should not need a j-mod!!!

Yeah, but I still want to modify the seperator plates and remove the 2-3 to firm the shifts...

I was just going to put a TransGo kit on mine...
I heard TransGo is ill-advised...
 
the trans go is fine i had it in my last tranny, but the shifts where not as firm as i want them to be so im going boumann.
 
If you guys would rather install an aftermarket shift kit, instead of modifying your transmission in a way it was designed to handle, go for it.

I have a whole box of Baumann's aftermath, and a trans-no-go pile of shrapnel at my shop. the inside of the 1-2 bore in a 97 trans looks like a cheese grater thanks to a trans-go kit with a "shimmed" lower spring that let go on the drag strip. it isnt pretty.

I have no experience with a baumann, or a trans-go kit, but i have read way too many horror stories about them. I have only read 2 "failed" JMOD tranny stories, and both of them were performed incorrectly.

a "glorified homemade shift kit" it is NOT. An alteration to the flow path of fluid derived from "un-modifying" closed passages from the factory is MORE like it. These trannies were designed to shift firm, and were 'toned down' to suit the buyers. All the JMOD is doing, is putting it back to the performance level it was designed for.

Furthermore, the JMOD entails more than just the replacement of the shift accumulators, so yes... you CAN JMOD a 98 Mark VIII!
 
i heard alot of good things from both , from guys who have been doing trannys for years. so go with what ever works , trans go , j-mod, boumann. prob do the j-mod since it the cheapest and it works well! my 0.02!
 

Members online

No members online now.
Back
Top