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#2457861 - 02/26/18 11:09 AM A518 full manual issues!
Charged392 Offline
member

Registered: 02/26/18
Posts: 9
Loc: Florida
Ok first off new to the forum I live and breath MOPAR! Have three of them now! 2012 6.7 mega cummins! 2005 392 hemi front mount turbo! And soon to be 2005 6.7 cummins swapped 1500!

Any way to the ? At hand. I have a a518/46rh trans I built it awhile back using the PATC stage 3 700hp kit and used the Fairbanks kit and set it to competition. Trans worked like a dream then I wanted more fun so went to the tfod-3 full manual. I went back and swapped the few springs that were changed back to stock and then swapped what was needed with the tfod kit. I was getting the slightest of what I would think was an overlap on the 2-3 shift and I was going to install the restrictive to fix this issue but then it all went south.

I now have a new issue. The 1-2 2-3 shifts now under decent accel or wot will bond to the point of tire drag and driveline lock every time at any rpm. Here’s the kicker if I take say 1 to any rpm and hold steady in a no load type sense and shift it is crisp and clean dead on same with 2nd gear and even 3-4. My issue is this only happens with a decent load on an accel.

The governor is blocked off per the instructions and line pressure screw is set to 2.25 turns out the TV arm is wedged at around 75-80% range.

Anyone have an idea of where to look. I have billet front Servo cover only stock piston with new seals and billet accumulator piston with solid block in there and the OD piston also.

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#2458101 - 02/26/18 06:59 PM Re: A518 full manual issues! [Re: Charged392]
Charged392 Offline
member

Registered: 02/26/18
Posts: 9
Loc: Florida
Anyone?

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#2458134 - 02/26/18 07:52 PM Re: A518 full manual issues! [Re: Charged392]
dizuster Offline
master

Registered: 01/12/05
Posts: 3388
Loc: Oakland, MI
The only normal way 1/2 can overlap is if the low/reverse band is stuck on. But it's obviously not because it's overlapping 2/3 also which has nothing to do with the low/reverse band. It almost sounds like its got a loose or cracked valve body that it's applying throttle pressure to the back side of the shuttle valves for the shifts, but that's odd too since it sounds like you have the kickdown lever tied in one position.

Give the board some time, there are some smart guys on here, they may just not check the forum every single day.
_________________________

Owner of the ugliest turbo car on the planet. 9.55-141.8mph @3740lbs on 275's

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#2458154 - 02/26/18 08:21 PM Re: A518 full manual issues! [Re: Charged392]
DaveRS23 Offline
master

Registered: 01/20/03
Posts: 4801
Loc: Benton, IL.
I tried installing the Transgo full-manual shift kit in my 518. Couldn't get it to work right. So I had A&A build me a forward manual valve body with a couple of custom touches.

Works like a dream.

As to the 2-3 overlap. I have struggled with that on 727s and 518s for years. After trying a bunch of different things suggested by the experts, I have found only ONE sure-fire way to get the 2-3 overlap out.

Use the Dorman 3/8" expansion plugs (#555-115) in the clutch passage. Start with a .090" hole. There will likely be a 2-3 flair-up . Then open the hole up a couple thousandths at a time until the flair is gone. Numbered drill bits #43 to #38 are handy for this.

If you go too far and need to back up, just run a screw into the hole and pull it out with a claw hammer.

Now, it is a very fine line between a small flair at WOT and the light throttle bang of slight overlap. You may have to choose between the two as I have had instances where I couldn't get all the light throttle slap out without having a little WOT flair or vice versa.
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KOS

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#2458156 - 02/26/18 08:22 PM Re: A518 full manual issues! [Re: Charged392]
Transman Offline
super stock

Registered: 03/27/11
Posts: 894
Loc: Michigan
I think Scott is close in his assessment - your problem probably lies in the governor plugs/shift valve/throttle valve valve train.

The fact that you get a clean 1-2 and 2-3 on a steady state throttle shift lets us know the L/R band is not hung up and likely the front band is ok too. Sounds like maybe the throttle pressure/kick down valve assembly is your culprit.

Not knowing what this kit has for parts and what it has you doing - I would return it back to stock and see if things get cleaned up.

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#2458160 - 02/26/18 08:28 PM Re: A518 full manual issues! [Re: Charged392]
Transman Offline
super stock

Registered: 03/27/11
Posts: 894
Loc: Michigan
Almost 50 years of building 727's and I never understood why guys get overlap or flare - then try to fix it with restrictors.

It's all about timing - front servo spring/s rates along with operating lever ratios and front clutch release springs.

Everyone says you can't use a 5.0 lever - can't remember ever feeling an overlap or flare on any six bbl or hemi trans from the factory and sure as hell never experienced it on the track with any race car.

I use a 3.8 lever in most of my builds but only because there is no performance difference between the two levers and the 3.8 are a dime a dozen.

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#2458188 - 02/26/18 09:02 PM Re: A518 full manual issues! [Re: Transman]
DaveRS23 Offline
master

Registered: 01/20/03
Posts: 4801
Loc: Benton, IL.
Transman, you may not understand why some of us resort to restrictions to cure flair or overlap, but it is quick and effective. Any other fix is usually much more difficult, but no more effective.

With the higher line pressures, and modified valve bodies being run today, the varied combinations guarantees that there will be some cases of 2-3 timing issues and 1-2/2-3 shift splits.

Heck, even the shift kits come with a restriction for that very reason.

If a customer comes to you with either a flair or light throttle clunks, how do you address it if you don't use a restriction?
_________________________
KOS

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#2458209 - 02/26/18 09:39 PM Re: A518 full manual issues! [Re: Charged392]
Transman Offline
super stock

Registered: 03/27/11
Posts: 894
Loc: Michigan
Its my opinion that some people resort to the restriction partly because it's in the kit and because they hear some people say it works. It's easy to install too if after building your trans you get overlap.

And it's easy to understand for those people - those that look at the trans clutch/band application charts that see on the 2-3 the front band is coming off and the front clutch is coming on. So they theorize that since the band is coming off - in order to have an overlap it must be the front clutch causing the problem by coming on too soon.

They feel something has to be coming on too quick to cause the overlap so conventional wisdom says slow that application down. Hence the restrictor.

I correct the flare in someone else's trans by installing the matched package of front clutch release springs (these have a direct impact on the 2-3 apply even though many call them release springs as do I) clutch pack clearance (minimal impact from this if within the span of correct specs), the front servo spring package and the operating lever ratio. Many of the guys doing transmissions do not understand hydraulically what is actually happening on the 2/3 shift.

Yes, they know what's on and what's off and the hand off on the gearchange but hydraulically they don't understand.

Not sure if this is a good analogy - your car has a terrible stumble on WOT at low speeds - it's got an AVS which actually has a loose air valve spring. Do you adjust the spring or choke the engine down with a small air cleaner (restriction) and drive down air flow?

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#2458225 - 02/26/18 10:50 PM Re: A518 full manual issues! [Re: dizuster]
Charged392 Offline
member

Registered: 02/26/18
Posts: 9
Loc: Florida
Originally Posted By dizuster
The only normal way 1/2 can overlap is if the low/reverse band is stuck on. But it's obviously not because it's overlapping 2/3 also which has nothing to do with the low/reverse band. It almost sounds like its got a loose or cracked valve body that it's applying throttle pressure to the back side of the shuttle valves for the shifts, but that's odd too since it sounds like you have the kickdown lever tied in one position.

Give the board some time, there are some smart guys on here, they may just not check the forum every single day.


Yes lever is tied at 80% range this weekend I was planning to try and move it to 100% and see if that does anything.

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#2458319 - 02/27/18 09:35 AM Re: A518 full manual issues! [Re: Transman]
DaveRS23 Offline
master

Registered: 01/20/03
Posts: 4801
Loc: Benton, IL.
How about a few questions for the restrictor resister?

What is the down side of using a restriction in the front clutch port?

Is the only alternative tranny disassembly?

Why don't the shift kits offer any alternative to the restictor they include?

And your carb analogy is flawed because a) the alternative is not a fix for the original problem and b) the alternative creates other problems.
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KOS

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#2458380 - 02/27/18 10:59 AM Re: A518 full manual issues! [Re: DaveRS23]
moparx Offline
Dreaming of implants

Registered: 09/03/03
Posts: 9729
Loc: north of coder
i tap the restrictor port 1/8-27 NPT deep enough to use a recessed hex [allen wrench] pipe plug that goes slightly below the valve body mating surface. i then drill various holes in the plug or plugs to tailor the overlap to my liking. easy to unscrew the plug to change or drill the hole larger. can even be done with trans in the car, as the hole is just slightly larger than the hole size needed for the tap, and a shop vac takes care of the few chips remaining [if any] after tapping with grease applied to the tap. reminder, you don't need [or want] to crank the plug macho/mucho tight. it can't go anywhere with the valve body installed. no sealer needed as well.
beer

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#2458419 - 02/27/18 12:16 PM Re: A518 full manual issues! [Re: Charged392]
Charged392 Offline
member

Registered: 02/26/18
Posts: 9
Loc: Florida
Ok going to give the TV 100% applied a test and see what that does. If that doesn’t do anything does anyone know where about a a crack is common to form on the VB so I can have a look and see if that’s the issue.

If I find no cracks and the TV cable doesn’t fix it I am going to take the trans out and completely go thru it like a rebuild to make sure I don’t have a planetary or something stupid going out possibly. If that’s all good I guess I will just order a full manual valve body from somewhere any suggestions on where to get one. Has to be standard pattern not reverse.

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#2458461 - 02/27/18 01:33 PM Re: A518 full manual issues! [Re: Charged392]
Transman Offline
super stock

Registered: 03/27/11
Posts: 894
Loc: Michigan
DaveRS23 - you can lead a horse to water......

If you want to use the restrictor that's obviously your choice. Go for it.

I never use them and any professionally built trans I have seen doesn't use them either.

The restrictor is for the guys that likely don't want to pull the trans or don't know the combination of parts needed for a clean 2-3.

And you obviously mis-read my post - I said i didn't think it was a good analogy.

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#2458472 - 02/27/18 02:09 PM Re: A518 full manual issues! [Re: Transman]
DaveRS23 Offline
master

Registered: 01/20/03
Posts: 4801
Loc: Benton, IL.
Transman, your way may well be much better than the way I, Transgo, Fairbanks, etc, etc do it.

But guess what? Your way is a secret. So we haven't been able to do a comparison.

I, for one, am open minded to new and better ways of doing things. Which is why I have a 518 rather than a 727, in my Cuda.

The only reasons I support the restriction is because it works every time, and because I do not know of a better alternative. You have the opportunity here to change may mind.

Why don't you share the details of your better overlap fix, so that we can try it and assess it for ourselves?

And I didn't misread your post, I was just pointing out why I agreed with you that you used a poor analogy.
_________________________
KOS

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#2458496 - 02/27/18 02:57 PM Re: A518 full manual issues! [Re: Charged392]
dizuster Offline
master

Registered: 01/12/05
Posts: 3388
Loc: Oakland, MI
I'm not sure how anyone would know which springs to tell you to change to in this imaginary overlap scenario? Every combo is different depending on the parts/clearances you use will require different springs for shift timing.

If 2/3 is overlapping, then the front clutch is coming on faster then the 2nd gear band is releasing. The longer the two clutches overlap, the more drag, heat, friction, power loss there is. If the front drum is already applying quick, then releasing the intermediate band quick is the best solution to minimize the total shift event time right?

Adding a restriction to apply the front clutch pack slower just makes for longer/softer overlap and mushy ET robbing shifts. The reason the shift kit manufactures do it that way, is because it's cheaper to give you an orifice to install then a set of springs.
_________________________

Owner of the ugliest turbo car on the planet. 9.55-141.8mph @3740lbs on 275's

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#2458510 - 02/27/18 03:22 PM Re: A518 full manual issues! [Re: Transman]
John_Kunkel Offline
I Live Here

Registered: 01/20/03
Posts: 19826
Loc: Rio Linda, CA
Originally Posted By Transman
So they theorize that since the band is coming off - in order to have an overlap it must be the front clutch causing the problem by coming on too soon


Isn't that the actual issue? How do you theorize it?


Quote:
I correct the flare in someone else's trans by installing the matched package of front clutch release springs....



Doesn't the correct spring package prevent the clutch from applying "too soon"? So the clutch applying too soon is the cause of excessive overlap?

Of course, you realize that some overlap is necessary to prevent flare up. Thus, the issue becomes some overlap versus excessive overlap which, in mild cases, is often construed as a firm shift. Trying to choreograph the perfect overlap by manipulating parts is, indeed, the correct way to approach the issue; problem is, how do you know when you have the perfect combo?

In every case it's a "seat of the pants" judgement, what the driver perceives as a clean shift with no flare up or overlap when, in reality, excessive overlap might be present and not recognized as such because of other factors.

Bottom line is, the TF will always be inferior to some other makes because of this release/apply sequence. As to the restrictor orifice, correct parts that result in a perfect sequence won't account for eventual wear of rings and clutches that will interrupt the perfect sequence, so I see the changeable restrictor as a valid method not a Band-Aid.
_________________________
I'm supposed to respect my elders, but its getting harder and harder for me to find one now.

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#2458543 - 02/27/18 04:39 PM Re: A518 full manual issues! [Re: Charged392]
Transman Offline
super stock

Registered: 03/27/11
Posts: 894
Loc: Michigan
Scott - your dead on.

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#2458581 - 02/27/18 06:38 PM Re: A518 full manual issues! [Re: Charged392]
DaveRS23 Offline
master

Registered: 01/20/03
Posts: 4801
Loc: Benton, IL.
Originally Posted By Charged392
Ok going to give the TV 100% applied a test and see what that does. If that doesn’t do anything does anyone know where about a a crack is common to form on the VB so I can have a look and see if that’s the issue.

If I find no cracks and the TV cable doesn’t fix it I am going to take the trans out and completely go thru it like a rebuild to make sure I don’t have a planetary or something stupid going out possibly. If that’s all good I guess I will just order a full manual valve body from somewhere any suggestions on where to get one. Has to be standard pattern not reverse.


Again, I am very pleased with my A&A forward manual valve body. I had them soften the 1-2 shift and lower the reverse pressure.

Tell them what you want and they can tell you if they can get it done for you.
_________________________
KOS

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#2458585 - 02/27/18 06:48 PM Re: A518 full manual issues! [Re: dizuster]
DaveRS23 Offline
master

Registered: 01/20/03
Posts: 4801
Loc: Benton, IL.
Originally Posted By dizuster
I'm not sure how anyone would know which springs to tell you to change to in this imaginary overlap scenario? Every combo is different depending on the parts/clearances you use will require different springs for shift timing.

If 2/3 is overlapping, then the front clutch is coming on faster then the 2nd gear band is releasing. The longer the two clutches overlap, the more drag, heat, friction, power loss there is. If the front drum is already applying quick, then releasing the intermediate band quick is the best solution to minimize the total shift event time right?

Adding a restriction to apply the front clutch pack slower just makes for longer/softer overlap and mushy ET robbing shifts. The reason the shift kit manufactures do it that way, is because it's cheaper to give you an orifice to install then a set of springs.


I agree with most of your post. But I do not feel that the restrictor softens 3rd gear engagement at all. It delays the the application of the clutch pack by slowing the filling of the void. But once the void is filled, the application is quick and firm. Even when I have had too small an opening which caused a flair, the tranny went into high firmly. Not the least bit mushy. twocents
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KOS

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#2458643 - 02/27/18 09:18 PM Re: A518 full manual issues! [Re: Charged392]
Charged392 Offline
member

Registered: 02/26/18
Posts: 9
Loc: Florida
I sent an email to A&A waiting to hear back from them!

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