B&M Shift Improver Kit

[Todd]

A word of warning...
I recently purchased a B&M Shift Improver Kit for my 93XLT that works with the vacuum modulator on my A4LD transmission. Well, needless to say, after the 5 minute install took me more than 1 hour, the unit was thrown into the garbage.
The kit comes with vacuum line, a special muffler, and a control unit(basically a valve). There is a T inserted into the vacuum line prior to entering the tranny. This then runs to the controller and then to the special muffler. It basically creates a vacuum leak in order to lessen the amount of vacuum that the modulator on the tranny sees. By doing this, it will increase the firmness and shift point of each shift. I tried installing the unit and everything went well. However, after starting the car, I noticed that the controller(mounted in the cab since it was adjustable) was leaking and was fairly loud. So, I started with just a little silicone to stop the leak. That did not fix it. I added more and more until it looked like a baseball of silicon. By this time I was really getting frustrated, so I let the silicon completely dry overnight before starting the vehicle again. Sure enough, the dumb thing still leaked. So, I was frustrated and to the trash bin the controller went.
I did retain the muffler and T fitting however. I simply hooked the muffler straight off of the small diameter supplied vacuum line and created my own vacuum leak. In actuality, the tranny shifts ten times better than it ever did. It also shifts more firm and at a little higher of RPM's now.
Whether this will have any adverse effects on the tranny is unknown. I don't think that it should, but we will find out. That is why I have an aftermarket warranty. Dead Link Removed
Take care everyone and happy exploring!


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Todd Metzger
tmetz@umr.edu
'Off-Road and More!'
93 "Ford X 4" XLT

 

[Hank]

Thanks Todd,

I was looking at the same thing on the B&M web site yesterday. I thought it was nothing more than a controlled vacumme leak. (aka fish tank valve in a plastic case)

My question for you and or others is: Do I really want the firmer and higher shift points? When my vac. modulator went south I had the same, although exagerated, thing. It sounds to me like this does nothing but put a higher load and rougher shifting on the tranny. I'd rather go the other route and use the Redline high temp ATF as people are reporting smother shifting. Am I missing something here?

I do lots of towing with a 1500lb and 3200lb trailers (total load) and the stock tranny setup seems to be fine. Even with the 31's

I welcome your input.

Thanks in advance.
hg

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'91 EB, 4dr, 2wd

 

[Todd]

Hank,
Now, I may be wrong here, but I was taught about tranny's from some definite old school train of thought people. They always used to say that a little firmer than stock shifting actually helped the life of the tranny. They stated that when a tranny shifts very smoothly, clutches and bands basically slip to create this effect. They used to always say that the firmer shifts reduced this slippage. Now, they also used to say that too much firmness would eventually destroy an automatic tranny.
Now, if I am wrong here, someone please correct me, but it has always made sense to me.
I would say that the firmness of the shift almost(in actuality) boils down to... "How do I like the shifting?" It is, in my opinion, similar to a user designated field.
Hope this helps a little, take care and happy exploring!


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Todd Metzger
tmetz@umr.edu
'Off-Road and More!'
93 "Ford X 4" XLT

 

[SteveVB]

Im going to agree with Todd about the trans shifting. The firmer shifts cause less slippage and result in less heat transfered to the fluid. Comfortable shifts are a result of a longer clutch engagement - I think, although new lining material (technology) may also allow smoother shifts without having to lower the shift points. Im a believer that the firmer, the better.



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Steve VB
91 Navajo
2 1/2" Rancho,
31" Goodyear AT/S

 

[Hank]

Thanks guys,

It does seem to make sense. Todd, keep us posted on how it goes in the future. For now I think I am going to start by changing the fluid to the Redline ATF. I got the dealer to put in a new filter and modulator shortly after I it, about 4000 miles ago so I am in good shape there.

Best regards.
hg

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'91 EB, 4dr, 2wd

 

[Francis]

Never forget that the A4LD tranny is a very sensitive and weak tranny...

Firmer shift---> Good on the clutches but bad on hard part...

Smooth shift---> Better on the hard parts wich I said were weak in the A4LD...and rougher on the clutches....

But remember clutches are cheaper to replace/repair... when a hard part brakes in a tranny... it usually destroy everything else...

I had my share of trouble with A4LD trannys (bronco II, Explorer)... I having my explorer's rebuilt right now...
I would'nt recomend(And my mechanic thinks this also) modifying and A4ld unless it for adding heavy duty parts... I was also told to never tow anything with an A4Ld...

Just think about that...A4Ld trannys started in a pinto.... Just a tough....

Use Synthetic Oil....It's really worth the extra cash!!!

Have fun


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Francis Lavoie

92 Sport 4X4
88 Bronco II 4X4

 

[Hank]

Hey Jon,

Can you get your hands on the right part numbers and post them? I'd file it for the day mine goes. And yes, please let us know if you like the shift kit. With all the towing I do I am sure the blow out the original tranny soon. Hopefully still under the used car warranty. I already got them on the seals.

Best regards.
hg

 

[FMExplorer]

Hey guys,
Here's a little insight on the A4LD tranny. Ford did actually beef them up - however - as I found out this week having my 2nd one rebuilt - most shops don't put the right parts back in them! The overdrive band and related hardware will fit from a 3.0 litre tranny, however, they can not handle the torque of the 4.0. Any tranny rebuilt with the 3.0 parts will be lucky to get 40k miles from it. I am in negotiations right now with the national firm that rebuilt mine. My goal is to get them to pay for the rebuild as they put the wrong parts in. (And I found out their policy is to put in the wrong parts). It's funny - build something to last past the warranty and people seem happy. My advice - make absolutely certain you get the right bands and hardware - or you will be spending way too much. Also - I am having a Tru-shift shift kit installed - and warranted - update to follow.

Jon M

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Jon McLeod
'93 XLT
K&N Drop-In
Kenwood Audio
Rancho RS5000's

 

[Chad Summers]

Hey guys.. a few questions.. first, if the b&m kit is only a vacuum leak, how do I make my own? (any suggestions on parts I guess is what I mean) Also if my tranny does go on me (or should I say when..), how do I make it stronger? I only have 52k right now but my x is geared real high for my area (lots of hills and 3.27 rearends aren't making me to happy, my aunt's 3.55's were about right) I dont' figure it will last to long.. Just from what I have heard, the firmer shifts are easier on the clutches (just like riding a clutch wears it out) but I would guess someone who wants the firmer shifts is also harder on their vehicle and that would cause the premature failure from harder shifts? Thats my guess anyway..

 

[Todd]

Well, it has been a while since I posted last, but to answer your questions Chad, I have risen from the dead. It is been about a year and a half since I sold my Explorer, but I do remember an awful lot about it. First of all, don't make your own shift kit. It will eat the vacuum modulator alive. It did on mine. Then, shortly there after, the tranny died. Unless things have changed, I don't know of any way to beef up the A4LD with the exception of a B&M valve body separator shift kit, an external cooler, and/or maybe a deep sump pan. Now, what I was planning on doing right before I sold it was to drop in a 302 and a C6 to solve all of my engine and tranny probs. Would have been nice.

PS (forgot this one) In town, run around in drive and only use overdrive on the highway when you are not towing or hauling anything heavy. The overdrive is notiously weak.

 

[Chad Summers]

Ok, thanks.. I usually only use od in mine because the biggest part of my drive to work is interstate.. I have to drop to drive to go up the one mountain though.. I had thought about switching to a 302 and aod.. is that tranny any better? I can't really afford to drive this thing without od or I would just drive my old 84 f150.. (hmm... I am kinda against the swap though because I only have 52k miles... be a shame to pull that stuff so early in life.. hehheh)

 

[Todd]

Chad,

I wouldn't do a swap just yet, the 302 and C6 was inline for me because I was building a good trail rig. If you do the swap, I would go with a C6 and not an AOD. The AOD is a good tranny, but the electronics can be a pain. The C6 has a more simple install, design, and ability to be rebuilt easier. I would just keep up on the maintenance of the tranny, maybe add the valve body separator kit, deeper pan, and external cooler. You should be able to add all of this for around $150. Heat and smooth shifting can kill an auto tranny. Hope I helped a little.