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Marauder.45
04-14-2006, 09:15 PM
Any truth to using a Mach 1 valve body to stiffen shifts?

I'm fairly leery of cracking the tranny, but need to stiffen the shifts since I installed the 3500 stall. You know how if it ain't broke, don't fix it. With my luck I'll crack the tranny and less than 5k later it will go kaplooey!

I have the J-mod directions, but feel uncomfortable drilling in the tranny. See above sentance.

SergntMac
04-15-2006, 04:44 AM
I wouldn't expect to find any differences in the valve body. However, shift schedules and line pressure come from the vehicle's tuning, and I am sure you will find some difference in a side by side comparasion of the programming.

TooManyFords
04-15-2006, 07:42 AM
.45 is correct. The mach 1 valve body comes "modded" from the factory for faster shifting. I suspect though it will be a tough or expensive find just for that piece.

John

SergntMac
04-15-2006, 09:06 AM
So, it's the same valve body, with a J-Mod from the factory?

Great...More stuff we didn't get in buying a Marauder.

MarauderMark
04-15-2006, 09:11 AM
So the mustang valve body is better to get/use than just getting a tune?

Marauder.45
04-15-2006, 10:04 AM
I wouldn't expect to find any differences in the valve body. However, shift schedules and line pressure come from the vehicle's tuning, and I am sure you will find some difference in a side by side comparasion of the programming.

Hey Serg,

Is line pressure a tuneable feature to an SCT chip tune? If so, what do you do?

SergntMac
04-15-2006, 10:35 AM
Hey Serg, Is line pressure a tuneable feature to an SCT chip tune? If so, what do you do? Within certain limits, yes. It's in the Pro Racer software, and available from your tuner. Word of warning though, do not mix physical "J-Mods" with software tweaking, they are redundant systems.

Marauder.45
04-15-2006, 01:27 PM
Thanks SergntMac, I'll ask my tuner about the Pro Racer software.

I don't want to crack the tranny until I nuke it, then I'll mod away from day one. So tune tweak for now suits me fine. thanks

TooManyFords
04-15-2006, 05:39 PM
There are two issues at work in our trannies. The first is the physical line pressure; how much there is to do the work and the second is the speed at which the servos can fill before a shift can take place.

You can up the line pressure to make the shift firmer, but only by opening up some of the holes in the pressure plate can you also decrease the time it takes to command the shift.

But Mac is right, you really need an expert like Jerry to make sure you don't go overboard with both mods and cause catastrophic failure.

I'm also interested in this mod right now so I'll also pass on any info I find useful to the collective.

Cheers!

john

David Morton
05-03-2006, 04:07 PM
In the "good old days" we used to take the checkballs out of the 2nd and 3rd clutch passages on TH350s' and 400s' for drag racing. They were there to block fluid going into the clutch housing and piston sending it through an orifice in the spacer plate. Hydromatic wanted the fluid to come out fast when a clutch was coming off, and that would push the checkball off the seat. When it was gone the fluid had a very big hole to go straight to the clutch and BANG! , boy did it come on hard.

I never saw that cause a clutch to fail or break. In automatic transmissions where the clutches are wet, faster application is always better, for the clutch pack that is.

But we can break other things overdoing the bang shift thing, like roller clutches and sprags.

My experience suggests that with the electronic management of fluid pressure and shift scheduling, the best route to go might be to use the best mechanical fluid management (re: fastest) where passages, valve bodies and spacer plate orifices are concerned and detune the hard shifts where and when necessary with programming.

I'll be keeping an eye on this thread. Good stuff here.

STLR FN
05-03-2006, 10:42 PM
Try this:
http://www.factorytechtransmissions.c om/ProductImages/sepplatekit.gif

http://www.factorytechtransmissions.c om/index.asp?PageAction=VIEWPROD&ProdID=20

or this:
http://www.factorytechtransmissions.c om/ProductImages/valvebody4R70W.gif

http://www.factorytechtransmissions.c om/index.asp?PageAction=VIEWPROD&ProdID=6

Some F-150 owners use the valve bodies in the 4R70W tranny. And if the 75W is just an "upgraded"(use lightly) version of the 70W then the valve bodies should be the same.

juno
05-04-2006, 05:47 AM
I am having a custom valvebody built for my specific needs when the PA goes in. Relativley inexpensive at $315. I can swap out the valve bodies and keep my stocker. Let me know if you want any info.

Rider90
05-04-2006, 06:04 AM
Try this:
http://www.factorytechtransmissions.c om/ProductImages/sepplatekit.gif

http://www.factorytechtransmissions.c om/index.asp?PageAction=VIEWPROD&ProdID=20

or this:
http://www.factorytechtransmissions.c om/ProductImages/valvebody4R70W.gif

http://www.factorytechtransmissions.c om/index.asp?PageAction=VIEWPROD&ProdID=6

Some F-150 owners use the valve bodies in the 4R70W tranny. And if the 75W is just an "upgraded"(use lightly) version of the 70W then the valve bodies should be the same.
FactoryTech's website used to list that valve body as compatible with a 4R75W - how do I know? I've hit this same idea in the past. They took it off their website for a reason, one I do not know, but if it did work FLAWLESSLY they would have kept "4R75W" on their site to get some more customers. I'd be weary about this mod, it sounds like it should work, but Factory Tech backed out.

The evidence of having 4R75W listed on their website was in Google's cache file, which has since been updated when referencing that page.

Krytin
05-04-2006, 10:09 AM
With my luck I'll crack the tranny and less than 5k later it will go kaplooey!

I have the J-mod directions, but feel uncomfortable drilling in the tranny. See above sentance.

The only thing you drill is the seperator plate that is sandwiched between the case and the valve body. You have to take the plate out to drill it so you can't damage the case. DO NOT raise the line pressure in any way when performing this mod!! You can purchace a new plate from the Ford parts dept. if you want to return to normal.

I have over 25k miles on this mod with no problems!