I've got an 89 dx tranny that needs new synchros and an 88 si laying around with a bad differential.

I was considering the following project in a few months, feedback on how difficult, tools needed and possibility of such modifications would be greatly appreciated.

I want to take the Si gears out and put em into the DX tranny, leaving the DX 5th gear for better cruizing rpms.

Change the syncrhos.


Is this possible with basic tools, or do I need some 500$ tools from honda?

 

it's possible,
you don't need spacial tools
make shure you know how to use a feeler guage for bearing clearance
use the SI final drive though cause you'll rebuilt a dx trany if you don't
performance wise, you'r better with the si final drive

Kranked

 

the DX and Si tranny gears are the same, it would be stupid to do so...the only difference is the Final drive...

 

Ya....so i heard

But the final drive is based on the differential.....darn...I guess I'll have to find an si differential

 

Differential is the thing the final drive ring gear bolts to. You can have a bad differential and still have a good final drive., But its true only difference between a Si and a DX trans is the final drive. and some of the DX cases had smaller main bearings.

 

How tough is it to change a synchro?

Iève heard you need a shop press

 

Transitions are one thing I would always have a pro deal with.

I would never feel comfortable rebuilding my own unless I had pro help.

 

Ya but if you managed to do it yourself wouldnt you be proud

 

Grab a junked tranny and break it open. I got one for $20, got my helms, took it apart and put it back together. Very sweet learning experience, I havent put it in a car to test it but I dont think it would matter, I got it for $20 bc 2-4 synchros were gone.

 

K i have done that hybrid twice now



notice how the Si Diff is more beefier on the hole wherre the axles go in
u need a 8mm allen socket, if not u will peel it ( a bitch nut on the input shaft side)
after u take tranny apart, i would take the countershaft with 3/4/5th gear out of the Si along with the differential gear ring
take your DX 3/4/5th countershaft and replace it with the Si one and replace the DX diff ring gear with the Si one

remember that the Final Drive is the countershaft along with diff ring togheter

ur final product

always make sure that the pin on the diff has no play and is on good shape and

 

I am indebted to you sir

I dont know too much about the trannies yet, this hybriding you have done will put Si ratios to a dx tranny? I assume you use the Si differential? unless I can bolt the gear to the dx differential I have, I'm gonna have to find another si

BTW, those that have repleced syncrhos in the past, how much are they?

 

Don't forget that if you use the 88 input shaft, you'll need a new clutch, again. :S

 

I've never takens one of the honda transmissions down that far, but no I do not believe you need a press for that.

 

I think I said this before but the 1-5 gearset for the DX and the SI are identical. All that is different is the final drive, Get a shop manual because you need to recheck clearances when you mix and match parts but the SI differential is identical, the ring gear is different as is the countershaft that makes up the final drive.

 

what you see is one large bearing case setup and one small bearing case setup. DX transmissions came in both as well as did the SI depending on its year of manufacture. The differential is the same and will fit either case provided you use the correct bearings for the case. IM Mista Bone, he is the forum expert on D series stuff, particularly Transmissions<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDM 4G VTEC &raquo;</TD></TR><TR><TD CLASS="quote">K i have done that hybrid twice now

.


notice how the Si Diff is more beefier on the hole wherre the axles go in
u need a 8mm allen socket, if not u will peel it ( a bitch nut on the input shaft side)
after u take tranny apart, i would take the countershaft with 3/4/5th gear out of the Si along with the differential gear ring
take your DX 3/4/5th countershaft and replace it with the Si one and replace the DX diff ring gear with the Si one

remember that the Final Drive is the countershaft along with diff ring togheter

ur final product

always make sure that the pin on the diff has no play and is on good shape and </TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Don't forget that if you use the 88 input shaft, you'll need a new clutch, again. :S</TD></TR></TABLE>
Dont worry, I remmember that.

I've still got the 88 clutch lying around tho

 

virginia dude is correct
the diffs are alike, but not the same, the Si if beefier..
u can use a Si one on the DX, but u need to exhange bearings, i beleive (mista bone correct me please) that the Si has 55mm Bearings and the DX has a 45mm bearings and in most cases that destroyes the bearings and is smarter to get new ones... those bearings are bench press. and is a puta to take off BELEIVE ME

the easy way is just use the DX diff, and exchange the gear ring that bolts around it... be done. basically a small bearing Si tranny