it's done all the time in racing.

the thing to research is the fitment onto the mainshaft and countershaft and compatibility with the syncros, spacers, final drive. The other thing to sort out are which clearances should you use from which model if you start adding on gear ratios from another model.

if you look at the JDM ITR and the gearing and the final drive, you'll see that they've done it too. For the 4.785 FD on the JDM 98 Spec R instead of the usual 4.4 FD on the 98 version of the R , they put a GSR 5th onto the ITR S80 tranny in .


You're not in left field.

 

I was thinking the same thing awhile ago.having short gears for autoX but not losing any highway gearing.

how much would a frankenstien project like this cost anyway.

great topic

 

it's very tedious work and time consuming. basically you have to have a clean work area, be organized,be patient, and just follow the Helms manual while checking your clearances. From the threads of people doing this here, it's also a frustrating exercise.

Looking at the parts involved, you can understand why:

Countershaft

Mainshaft

it's a matter of disassembly and re-assembly but it's keeping them aligned and in sequence at the right clearances which requires some patience and experience.

If you're asking someone to do it for you and paying them you can see why it's going to take the better part of a day in man hours to do this with an experienced tranny guy.

 

some gears , spacers, bearings, and synchros must be purchased together and not separately from Honda.

 

it's very tedious work and time consuming. basically you have to have a clean work area, be organized,be patient, and just follow the Helms manual while checking your clearances. From the threads of people doing this here, it's also a frustrating exercise.

Looking at the parts involved, you can understand why:

Countershaft

Mainshaft

it's a matter of disassembly and re-assembly but it's keeping them aligned and in sequence at the right clearances which requires some patience and experience.

If you're asking someone to do it for you and paying them you can see why it's going to take the better part of a day in man hours to do this with an experienced tranny guy.

If you've got experience working on you're car and a good general technical skills it's really not all that bad.

Like MD said, get a helms, a clean well-lit work area, set aside plenty of time so you're not in a hurry, and be sure to oraganzie/label parts as you take them apart.

 

it's done all the time in racing.

the thing to research is the fitment onto the mainshaft and countershaft and compatibility with the syncros, spacers, final drive. The other thing to sort out are which clearances should you use from which model if you start adding on gear ratios from another model.

if you look at the JDM ITR and the gearing and the final drive, you'll see that they've done it too. For the 4.785 FD on the JDM 98 Spec R instead of the usual 4.4 FD on the 98 version of the R , they put a GSR 5th onto the ITR S80 tranny in .


You're not in left field.

This is one of my problems. Where can I get the specifications for the mainshaft, countershaft and syncros without having the actual parts in hand? I have my Helm's, but haven't spent much time studying the setup and clearances yet.

 

The Helms has in the tranny chapter/section: the synchro ring to gear, double cone synchro to gear and mainshaft thrust shim clearances (with the selection formula for the thrust shim).

 

I have never heard of any of the gears being interchangeable within the transmissions except the fifth gear. Also, they DO make as gsr tranny with an lsd. It is out of the JDM GSR s80 transmission. The only problem you will run into is the bolt patten which holds the lsd to the final drive. the jdm gsr s80 lsd has a 14 bolt pattern, the usdm itr, quiffe, kaz, or cusco lsd's are all made with a 10 bolt patten. you will need the proper final drive to corrispond to the lsd if you buy jdm. just a heads up that will save you alot of time if you ever decide to start swapping lsd's.

 

they make a 4.4 & 4.785 fd for the jdm lsd.

 

I have finally had the chance to study my Helm's manual. The job doesn't look too bad as long as I have all the parts that I need.

From going over and comparing the parts breakdowns the tranny's are pretty much the same. They even share many of the same parts.

This is what I have gathered that I will need so far, and am sure the list will grow.

Specil tools that I do not have:
1) 07746-0030100 (for pressing in the bearings)
2) 07746-0030400 (for pressing in the bearings)

For the mainshaft:
1) 4th gear from the GSR
2) 5th gear from the RS

For the countershaft:
1) 4th gear from the GSR
2) 5th gear from the RS
3) Locknut

If that is all I need, it's not going to be all that bad. However I haven't been able to find out whether I will need the synchro sleeves and hubs on the mainshaft. The synchro sleeves and hubs are sold as sets and cannot be purchased broken down. This leads to a series of questions.

1) The 5th/Reverse synchro sleeve and hub for the type R is the same as that of the GSR, but different for the RS/LS. So since I want to replace the 5th gear above, I am assuming that it is required for the swap as well. It's a fairly expensive part!

2) The 3rd/4th synchro sleeve and hub set is different for the R GSR and LS. Since I would want to swap 4th gears from the GSR, I assume that this set would also need swapped. It too is fairly expensive.

I am by no means an expert on manual transmissions, therefore I am somewhat lost on what exactly the synchro sleeve and hubs do and how they interrelate with the gears and how they synchronize them during shifting.

 

Any updates on this?

 

Correct me if I am wrong but I do believe there is an aftermarket 6 speed transmission for B series applications. I think I saw it in one of my Superstreet mags. I will try to locate it for more information.

 

Any updates on this?

No. I pretty much put this idea on the back burner. Couldn't come up with all the answers to the questions I had.

 

I've read that the GS-R tranny is bit restrictive for this. I own a 2kGSR and I know. If I was going to buy a tranny, I would try to track down a Civic Type R tranny with the LSD and 4.whatever final ratio. I have often considered and have came across a good deal($899).

I don't know if it's just hype, truth, or what but this is what I've read. Although I just checked my books and could not find the article, sorry. I promise I'm not spouting off at the mouth.

 

seperate parts and like put a sheet of paper next to it with the name of the part.

Take your time make sure its right when your closing the tranny back up cause its one of the most angering/depressing things when you put the tranny back on the car and you cant shift into any gear........

 

hey keep us informed because I was also thinkin about doing a tranny proj like this...good luck

and Tim, please post that aftermarket tranny if you can....maybe we can try and research it and get some more info.

 

Don't quote me on this but... I'm pretty sure there is a JDM gsr tranny that comes equipped with LSD, though I think it is kind of rare. Not 100% on that but more like 80% so don't quote me on it.

 

Okay, let me see if I can help you along...

-an LS 5th gear WILL, I repeat WILL fit with the type R's 5th/reverse synchro/sleeve set. I found this out for myself when I was rebuilding my ITR trans back in May. I also had a torn down LS trans so I did some checking. So, all you need for the 5th gear swap are the 2 gears that go on each tower to make up 5th, and NOT a new syncro set. Another thing that helps confirm this: go to acuraautomotiveparts.org and look up the part # for the 5th/reverse synchro sleeve set (#16339)... its the same for each hydraulic B series trans.

- My ideas to get your "GSR" 4th gear: easiest way to avoid fitment questions is to use a 98 spec ITR trans. Its a little expensive, but all you'd have to change out is 5th gear to get the frankenstein trans you desire. The 98 spec ITR trans shares 1st, 2nd, & 3rd gear ratios with the 96 spec/USDM trans, but 4th & 5th are the same as the GSR tranny, ie: 4th=1.034 & 5th=0.787. The question is whether the 4th peice on the mainshaft will match up with synchro sleeve and ring that are already there. The one thing I can think of if would be hook up with a company that sources the 4.785 FD from JDM-land and see if they could order the 3rd/4th syncro sleeve/ring kit for a 98spec JDM ITR from Japan.

if you're starting with a GSR or type R trans, you shouldn't have a problem using whatever mainshaft and main shaft already in the trans, unless you want to change final drive to 4.785 (a GREAT modification)

Don't quote me on this but... I'm pretty sure there is a JDM gsr tranny that comes equipped with LSD, though I think it is kind of rare. Not 100% on that but more like 80% so don't quote me on it.

uh, yeah thats been covered in this thread, I'm 100% that they are out there because an LSD was an option in the Japanese SiR-G.

 

I think your going to need a press to press all the gears and synchros back in place also.

 

FWIW, i got nearly ithe same gas mileage using my ITR tranny as i did with the ls. once you get use to being at 3000+ rpm on the highway its really not that big of a deal.

 

I think your going to need a press to press all the gears and synchros back in place also.

not true....I hammer and socket will work fine.

 

i'm greatly concidering doing the jdm4.7fd and an ls 5th in my gsr tranny. if i had another form of transportation i would do it right now, but since i'll be doing it myself and will need to take my time and have my car without a tranny for at least 2 days i'm waiting. but now that i know for sure the ls 5th will fit right on i might just go for it. i've played around with the gearing calculator and its a valuble resource. ive spent a little time looking through the helms and it seems feasable to do it myself as long as i'm diligent. heres a couple good links

this tread on t-i
that gearing calculator
a link about the 4.7 on h-t
and a full tranny teardown w/ fd and lsd install with great info and pics on h-t

-ryan

 

Sorry Christian I could not find the exact article in SuperStreet mag but the manufacturer was g sport racing or mr. g racing something like that. However I was able to come across some 6 speed fwd aftermarket trans. at http://quaifeamerica.com/. I do remenber that it was priced out of the range of most people.

 

plugging in the numbers for my setup(stock gsr tranny w/ 195/50/15's), my setup with the jdm 4.785fd, and all of the prevous but with the ls 5th i get these numbers for highway cruising. rpm @ mph in 5th

stock w/ 195/50/15
3077 @ 60
3589 @ 70
4102 @ 80

previous with jdm 4.785fd
3346 @ 60
3904 @ 70
4461 @ 80

previous 2 with ls 5th (.714)
3036 @ 60
3541 @ 70
4047 @ 80

i dont know how the ls 5th will affect changing gears between 4th and 5th. someone with more tranny and gearing experience please shed light on that.

-ryan

 

well i did it on a d-series trans i put three different trannies together. an si, ex, and vx. i put the shafts together and then tried each case to see if it would rotate in all of them and it did. you could just do that. but i mean honda used all the same exact parts they just used differnt numbers of teeth on their gears. i dont think your gunna have a problem. i remember seeing that 6 spd a while back to for a b-series but it was like 3800 i think. but im sure some of these jdm trannys will be just as much.