What is a shift kit? • The Dodge Challenger Message Board

by **bryan eidins woking surre** » 23 Jan 2002 20:45

can someone tell me what this is and what does it do,also i have a 727 i wnt to get rebuilt who does the best job in the uk,also is it worth having a shift kit fitted and which one to use.
many thanks in advance bryan

by **dave-r** » 23 Jan 2002 21:36

A shift kit makes the gear changes quicker and firmer and is used to slightly improve quarter mile times. Unless you intend to race your car it is not worth the hassle although as you say it needs rebuilding anyway it can easily be done at the same time. If you want to totally rebuild the trans you need something like the B&M Transkit. This contains all the parts and instructions to rebuild the 727 as well as modify it if you wish.

Other kits are cheaper but don't have good instructions.

If you never race your car don't modify it.

Duncan Watts is the MMA UK trans expert. People like Geof Hauser do it too.

It is not a hard job to do yourself if you use the B&M kit as the instructions are very clear when used in conjunction with the workshop manual.

I did mine myself but did miss an important seal out during the re-build. The trouble shooting guide in the instruction helped me pin-point the problem straight away so the only hassle was having to take the trans out of the car again to put it right.

A very rewarding job though. Now that I have done one I would love to do another!

by **Blue** » 24 Jan 2002 18:35

I've built quite a few 727's using B&M Transkits and find them excellent, I wouldn't use any other make now. The transkit includes a shift kit in the box. As Dave says you could have a go at it yourself,or I would be happy to do it for you (I'm in the London area)

by **bryan eidins woking surre** » 24 Jan 2002 22:41

cheers blue,is it possible to give me a price for the rebuild,where would i get the shift kit from.you can e.mail me on-

scoobydoobry@hotmail.com

by **Von (Von)** » 27 Feb 2002 15:49

Dave, have you done anything else to your tranny besides the b&m shift kit? I had mine redone with a trans go shift kit and i dont know if it is the kit or the guy that re built my tranny but bluntly put "It sucks!!" It is very hard to describe what it does exactly but it is not near like i want it to be. instead of it being a quick firm shift, it shifts hard but slow. i cant describe it. should i try to do a shift kit my self, or what? start whith a whole different valve body? the tranny is robbing so much power its unbelieveable. what about a stall? Does a stall effect daily driving and on the highway, or does it just help starts? if it didn't effect any thing esle i would consider one.

by **Dave R (Roppa440)** » 27 Feb 2002 16:18

All auto transmissions use torque convertors and all have 'stall' (the theoretical speed above which the engine can not go when the trans is in drive but the wheels locked so that they cannot move). The amount of stall depends on the torque output of the engine. More torque at low rpm = more stall speed. Advertised stall speed is very general and should be taken with a huge pinch of salt. Once the stall speed of a convertor is reached it almost stops slipping like a clutch and the engine and trans are in effect locked together so any driving you do above the stall speed is not effected.

I used the B&M TransKit which contains everything you need to re-build the trans as well as adjust the way the trans shifts. It sounds as if the guy that did yours has done something wrong.

by **John P (Blue)** » 27 Feb 2002 18:43

Von, I had trouble with a Trans go kit and also with a Hurst. The instuctions were badly written on both kits, meaning that the valve body had to keep coming out until I got it right, not fun! As I see it you have 2 choices here, take the box back to the guy and tell him to get it right, or start out with another valve body and a B&M kit and do it yourself.

by **Von (Von)** » 28 Feb 2002 4:12

I have built my car, I can build a jet ski or motorcycle motor or tranny from a box of parts. I could also build a car motor and plan to do so in a couple of months for another car. But have never messed with a car transmission. Am I capable of doing it. Yes I am capable of following directions. If you convince me that I can do it, I will probably do it. I know the guy that did mine had to drill some of the valve body holes out to increase flow. Maybe thats what makes it shift different. Like i said, i am totally clueless in this area. Thats the reason i ask if i would have to have a whole new valve body. also, i could re-do it just by droping the valve body out the bottom of the tranny, right? i wouldn't have to pull it out to get to anything right?

by **Dave R (Roppa440)** » 28 Feb 2002 7:52

When you say it shifts "hard but slow" do you mean it shifts late? i.e. You have to climb to high rpm before it shifts? If so there are a number of simple things that may be wrong that you could easily put right. Try to explain exactly the problem.

by **Von (Von)** » 28 Feb 2002 15:49

in a sense it double shifts. it doesn't skip the gears, its just not firm. i dont want there to be any hesitation. if one shifts hard you know how it will kind of throw you back a little bit? thats what I wanted mine to do. thats why I got the shift kit. it almost shifts as if it were a four speed and you put the clutch in to shift from first and you give it gas while in neutral then you dump the clutch after in second. the rpm it shifts at is fine. When I shift it manualy from first to second is when it does this. did you understand any of this?

by **Hans (72challenger)** » 28 Feb 2002 16:11

If I understand you right Von, the trans reacts like shifting in a 4-speed without taking your feet off the gaspedal? The engine revs a little when the trans is between the two gears...
I have sometimes the same thing with mine, but only when I shift by myself from first to second gear at a mid rpm speed. When I shift at about 5000-6000 rpm from 1st/2nd it has a good firm shift and at <2000 it shifts like a standard trans. But the trans is still alive so I don't think it will hurt the trans. Wouldn't have a clue what is causing the problem.

by **Dave R (Roppa440)** » 28 Feb 2002 17:19

I am not sure I quite understand but are you saying that when it does shift it comes in hard but before that the revs go up and it is slipping? Does this happen on the 1-2 shift or 2-3 or both?

by **Dave R (Roppa440)** » 28 Feb 2002 17:20

Before we go any further is the kickdown lever connected and adjusted correctly?

by **Von (Von)** » 28 Feb 2002 22:52

Hans has it perfect!! I do think my kickdow linkage is correct. What i am describing mainly happens on the 1-2 shift. It kind of makes a "klunk" sound. The 2-3 shift is fine but to me it seems like a regular trans. but the 2-3 shift brings about whole other disscussion. If I am in drive, and go below approx. 40 mph it down shifts into 2nd gear. and shifting on its own it will not shift into 3rd before 45 mph and it shifts nothing special. not hard, just shifts.

by **LITEMUP (Von)** » 01 Mar 2002 3:20

I will double check my linkage this weekend. how bout ya tell me any tricks in getting the kickdown linkage as precise as it can be.

by **LITEMUP (Von)** » 01 Mar 2002 3:22

how do yall like my new name? ha ha ha!!

by **Dave R (Roppa440)** » 01 Mar 2002 7:36

I have a thread in this section somewhere that explains how to do it step by step. I have also posted the trouble shooting guide from the B&M instructions so see if any of the problems they have listed ring a bell with you. There are so many things that could cause your prolem it might be easier just to re-do he whole trans. That would mean removing it from the car though because you need to check the piston seals and make sure you have the max amount of clutch plates and springs.

Rebuilding an auto trans is a job you can do in a day if you have done it before. I took mine out of the car one day (saturday), stripped it down the next (sunday), made a repair to the case and cleaned it up during the week, put it back together again over two nights during the week, installed and tested it the next saturday.

Then the weekend after I took it out again to install a piston seal I had missed and was causing it to slip!