Transmission Questions LS vs. ITR, Synchro Questions too!
 

I am trying to decide on the transmission for my next build. I already have an LS transmission from and old setup and i know it is in decent shape.
I have looked at many gear combinations and i would either like the LS transmission with a 4.785 final drive or a USDM ITR transmission which has the 4.4 FD.

1. I found some sources that say the LS has very weak syncros. Is that true?

2., Also, is it possible to put an itr diff and final drive into an ls tranny?

I cant decide if it is worth doing the work to the LS tranny or if i should just buy an ITR tranny. Doing the work doesnt bother me at all i am just worried about the final quality of the transmission.

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

Mistabone must be on vacation..

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

i thought that the LS/b16's trannys were incompatible with GSR type R final drives/diff's

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

I do very few B's, got ahold of my first GSR tranny, Y21 Cable LSD, quite rare, $500 in parts so far just to fix it.

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

They only made that one year, right?

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

Why would you want a ITR final drive in a LS?

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

I put an Infinitude 4.9xx(cant remember the last 2 digits) final drive in an ls tranny and its basically a b16 tranny with ---- synchros.
I like it but you may fall out of vtec when you have the stock redline.
Im now looking for a b16 tranny so I can slap this final drive and 5th gear in it and have a crazy city tranny

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

The synchros on the 3-4 in the LS and GSR are smaller than B16/R as is the fork diameter.

I would just try to get a US ITR tranny, since a 4.785, LS, and hypoid diff is gonna cost more than a ITR.


It really depends on what motor you are using, what redline, and what kind of torque curve you are aiming for to choose between LS gear spacings or ITR spacings. Final drive is looked at last.

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

So i have been researching the hell out of this topic and have learned a ton.

I picked up a 2000 Civic SI tranny (Same ratios as the USDM and pre 98 JDM ITR) that is in really nice shape. I have taken it all apart and ordered an ITR LSD. While i am in there i am going to add an LS 5th so that i am not cruising at 4500 rpms or higher.

I was a little nervous to start this but once i opened the case and started working through it with a service manual its really not any harder that doing anything else. There were a few clearances to check and i was careful to note the order in which everything needs to be reassembled. If you can rebuild a motor you can rebuild a tranny.

One other question. Is it normal for the top mainshaft bearing to have a decent amount of play? This thing moves up and down like a quarter inch but is very tight side to side.

Re: Transmission Questions LS vs. ITR, Synchro Questions too!
 

If you graph an LS with 4.785 FD and a the ITR with a 4.4 FD you get almost the same final ratios.

Also, when all is said and done i will have about $900 into this but i have gone over everything and it will have all new seals and bearings and i will know that everything is within spec. I couldnt find an ITR tranny for that cheap and it wouldn't have a sweet LS fifth. Plus i was a little nervous about sending over 1k to someone for a tranny i have never seen nor know the condition of. Plus, now i have a very good understanding of honda trannys.
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