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Discussion Starter #1
Ok..... so let me start out with saying this didnt happen before the Jmod that I put in and I've flogged it many times before.

So..... this shifts are nice and firm as should be, and it drives fine, however if I get on it and rev it past 3500rpm in first I hear a whining noise, and if I let up off the gas then the 1-2 shift becomes REALLY harsh almost like someone rearended me. It only happens with the 1-2 shift and only above 3500rpm, under that, no noise and prefect operation. I double and tripple checked everything that I did when I put the Jmod kit in and I'm kind of at a loss. I never heard this noise before the Jmod and I've taken it to 5K.

My Jmod settings are the mild settings, no 2-3 spring, brown lower and purple upper 1-2 spring, new accumulators as per Robert P's kit.

Any info would help.
 

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doesn't the purple spring go in the lower...
 

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That correct brown is upper and purple lower not really sure what happens when they are swapped there is no issues with the kit, I've installed prolly 30 of these and I have around 10 built transmissions with same type of mod, and we have only had one failure after the jmod but the trans had major issues, and the customer was just hoping it would fix it vehicle shifted fine first few tries then went to the rev limiter and shift ended with a bang very common on these transmission

Robert
 

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if you have your foot to the floor and let off just before the 1-2 shift occurs, a hard full line pressure shfit will still happen, as the EEC has already sent a command for such a shift a split second before you took your foot off the gas. Best to just keep your foot planted if possible.
 

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Discussion Starter #6
To clarify and avoid confusion, for the 1-2 I put back in its bore in this order..... brown spring-accumulator-purple spring-cap-snap ring (keep in mind that I was doing this on my back with the trans in the car so your upper might be my lower)

I understand about the command sent from the computer that could be causing the slam because of pressure, however what lead me to let up like that is hearing the whinning noise and not wanting to do any damage. I revved it in my driveway to 3500 and heard the same noise in park. I never heard that noise before I did the Jmod and didnt end up with 'extra peices' :rolleyes: I can get a vid so you can hear it and maybe see what it is a little better.
 

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- You might want to pull Battery Cable & let ECU reset just for giggles then PUTT around for awhile.

- I'm sure you've checked Tranny Fluid w/Motor running on LEVEL surface.

- My 1st guess is that this is incorrect JMOD installation - All of us sometimes can't see the forest for the trees.

- 2nd guess a Main VB problem that's been highlighted by the JMOD

- & / OR a 96 Tranny that's day of reckoning is near regardless of JMOD install.
 

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Discussion Starter #8
- You might want to pull Battery Cable & let ECU reset just for giggles then PUTT around for awhile.

I'll have to give that a shot. I know I putted around a little bit after I did the Jmod and it did feel 'weird' for the first mile or so but it's felt fine since

- I'm sure you've checked Tranny Fluid w/Motor running on LEVEL surface.

Checked, rechecked and rechecked. I really hate the dipstick because it tends to be tough to read at times

- My 1st guess is that this is incorrect JMOD installation - All of us sometimes can't see the forest for the trees.

As much as I would love to say "I'm perfect" I know that's not the case :rolleyes:. I did look through tech articles, topics and watched the jmod vid from DD MANY times before doing it. I could swear that I put everything in the way it should have been with the correct torque numbers. I'd really hate to drop the pan again...

- 2nd guess a Main VB problem that's been highlighted by the JMOD

:facepalm: I hope not....

- & / OR a 96 Tranny that's day of reckoning is near regardless of JMOD install.

The trans is the original one with 162K miles on it so nothing would suprise me. The ONLY thing that I can think I had 'issues' with was the converter chatter sometimes going into reverse or drive, other than that it shifted well and didnt chatter any other time.
Some answers in bold above. I really hope it's nothing major. If I dont get on it past 3500, it shifts nice and has no issues. Above that 3500, it makes that noise but still pulls as it should. It doesnt feel like it's slipping when it starts making that noise. I'm going to see about getting a vid so you can hear the noise.
 

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For a couple days after my JMOD was done, my trans shifted very strange...it would hesitate on shifts, and do other weird things. All of these issues sort of cleared themselves up, never to return. Even through computer re-flashes, bettery disconnect/reconnect/relearn etc. mine hasn't acted strange, so, for some reason, some cars will act weird right after a JMOD is done. This reminds me, it's time for me to do a fluid and filter change on my transmission.
 

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Some answers in bold above. I really hope it's nothing major. If I dont get on it past 3500, it shifts nice and has no issues. Above that 3500, it makes that noise but still pulls as it should. It doesnt feel like it's slipping when it starts making that noise. I'm going to see about getting a vid so you can hear the noise.
Indeed at 162K that Tranny owes you very little... mine was toast at 126K.
 

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Sounds like the additional pressure of the modifications finished off the roller clutch, there are warnings about it in the article. This is a prime reason why I do not liek to go very big on a stock mn-12 transmission unless a mechanical diode drum has been installed.
Alan
 

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Sounds like the additional pressure of the modifications finished off the roller clutch, there are warnings about it in the article. This is a prime reason why I do not like to go very big on a stock mn-12 transmission unless a mechanical diode drum has been installed.
Alan
One reference is Note 5 on Page 14 & a Note 2 @ Chart lower Page 13 of the Epistle fm Jerry - I'm sure Robt's Kit accounts for all that.

On Subject:

The Article shows a Pre 2001 Main VB Gasket & Sep Plate - Hole #6 in the current Revision of that Gasket is a Slot just like the Article shows.

In 2001+ Main VB the Gasket is different & has what I measured to be a .187 Hole @ #6, not a Slot - Article doesn;t cover 2001+.

Note 5 Page 14 says you CAN Slot Hole#6 w/Mech Diode & I took that to mean that .160 Drill size on Page 13 of the Article was THE OPTION @ Hole#6 for Mech Diode - It specs .125 @ Hole 6 for Roller (all MILD).

- When installing Mech Diode & TC fm DD to replace blown Rollers in my 96 I drilled Hole #6 to .187 like a 2001+ Main VB Stock Gasket has at Hole #6 - No complaints.
 

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If the snap ring was already on the edge even the minor mods were probably enough to help it off. It was sure to happen anyway and there was nothing that could be done about it. Shy of taking it out and fixing it.
Alan
 

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This was a mild kit but like dirtydog says the one way rollor may be failing that's what failed on that one trans but heck that's 1 out of 30 installs plus all the kits ive sold, which is around 40 or so I'd bet, but I doubt there's anything that would have stopped the sound unless left stock then it still might have happened
 

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Unfortunately your experience sounds like mine. I parked mine after it made that sound. I'm looking for a new trans currently. Mine went from aggressive 1-2 to sponge soft 1-2 with that whine.
 

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Unfortunately your experience sounds like mine. I parked mine after it made that sound. I'm looking for a new trans currently. Mine went from aggressive 1-2 to sponge soft 1-2 with that whine.
That does'nt sound like same experience / symptom as OP to me - Would'nt it just Nuetral once Roller toasted? - This sounds like something else.
 

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That does'nt sound like same experience / symptom as OP to me - Would'nt it just Nuetral once Roller toasted? - This sounds like something else.
Wanna come diag in my thread post then? From what I've been told roller clutch death is/was/could be 1-2 shift problems and it goes: whine... followed by rattling.... followed by neutral. I could be wrong though. I know enough to be dangerous with tranny building. A few classes and my own readings. Not much hands on in depth on the 4r70w lol but I can build a mean 4l60/700r4/4t60/4l80!
 

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The kits are drilled for the stock roller, as Alan said the mechanical diode trans do get a bigger whole were required

Robert
 
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