RX tranny linkage swap

[casm]

Hypothetically, let's say I had a line on an RX tranny with the centre difflock; it doesn't include the linkages (including the pivot arm) for the gear and 4WD shifters. Now - also hypothetically - let's say I found a junkyard RX with the non-centre-difflock tranny. Could I swap the linkages from the junkyard car to the pulled tranny I'm considering buying? The difflock tranny came out of a naturally-aspirated '87 RX, and the junkyard car is also a naturally-aspirated '87.

 

Yep, I'm looking at this as a potential swap into the Brat.

[baccaruda]

Is the RX without the diff lock an 85/86 5speed, or is it an 87-89 auto?

 

I'd think that anything can be fabricated to work; if you want a bolt-on solution then I'd put an ad in Wanted for some RX linkage. I think it is a bit different from a normal dual-range 5speed but not significantly.

[casm]

Is the RX without the diff lock an 85/86 5speed, or is it an 87-89 auto?

 

Should've been clearer on that. It's an '87 5MT, 4WD, no difflock that I could find. Verified age from emissions label. Vehicle is sitting on its belly, so no way to get under and look at the transmission.

 

I'd think that anything can be fabricated to work; if you want a bolt-on solution then I'd put an ad in Wanted for some RX linkage. I think it is a bit different from a normal dual-range 5speed but not significantly.

 

That's the thing - since I've got one RX sitting there with all the parts on it, it seems reasonable to infer that it should swap to the difflock tranny. I just don't know if that's the case, and would really prefer to avoid getting into fabbing stuff up if there's a stock swap that'll work.

 

Remember that even though I'm considering this for a Brat swap, my first priority is to get that difflock tranny back to stock form as regards the linkages. I know the swap will require fabbing, but I'm not looking at that part of things quite yet.

[Numbchux]

well, first off. All genuine RXs are turbo. and all 5MT RXs have locking center diff and dual range.

 

 

that said, the linkages from a part-time 4wd dual-range (any EA82 gl, very common) will work just fine. the hi-lo linkage is a bit shorter in the part-time setup, but it will work alright. and isn't too hard to lengthen (I cut it in half, cut some threads into it, and used a threaded coupler. worked great!).

 

and the diff lock solenoids are the same as anything with a push button PT4WD 5MT (loyales or DLs).

[casm]

well, first off. All genuine RXs are turbo. and all 5MT RXs have locking center diff and dual range.

 

Hm. OK. Maybe my understanding of what an RX actually is is off-base here. What I've got is a 3-door coupe, non-turbo EA-82, with the large hatchback on it. I always understood that bodystyle to be the RX (along with the sedan version), so my parlance was likely wrong.

 

that said, the linkages from a part-time 4wd dual-range (any EA82 gl, very common) will work just fine.

 

Cool, good to know. Thanks.

 

and the diff lock solenoids are the same as anything with a push button PT4WD 5MT (loyales or DLs).

 

OK, stupid question of the day: assuming this car has the difflock, where should I be looking for its switch? I thought it was on the centre console next to the 4WD lever, but there's nothing there.

 

Also, will splines and axle diameter match up from my Brat? I think I need to do some more research into the gearbox I'm considering acquiring: my understanding from what's been posted here is that if it's a difflock tranny it should have come from a turbo, but I don't know if turbo stub shafts will mate up to EA-81 axles.

[Numbchux]

all '87-'89 RXs are 3-door coupes. but not vice-versa.

also all '85-'86 RXs are sedans, but again, not vice-versa.

 

there are lots of sedans and coupes that are DLs, GLs, and GL-10s. available with many tranny options. only the RX coupes had the FT4WD AND dual range.

 

 

as far as I know, no non-turbo Ea82s were available with FT4WD with a locking center diff. only the turbos.

 

 

a genuine RX will have the regular 5-speed linkage. and then behind that (towards the rear of the car), a lever to shift from hi to lo, and a small electrical switch next to it to lock the center diff. the electrical switch controls a pair of vacuum solenoids on the driver's side strut tower, that directs vacuum to the trans to lock the center diff.

 

 

many standard EA82s had part-time 4WD Dual-Range trannies with just the hi-lo lever, that also selects FWD. the linkage from one of these can be used on a RX trans.

 

some Ea82s had part-time 4WD with single range. these had a button on the top of the 5-speed shifter to engage the rear end. this button controls solenoids identical to the RX diff lock one.

 

neither of these are a "diff lock", they are fully locked when engaged, but no diff, the other 2 wheels are just completely disengaged and coast.

 

 

 

I suspect the "diff lock" trans you have is a single range PT4WD trans, and the other is a dual-range PT4WD.

[casm]

as far as I know, no non-turbo Ea82s were available with FT4WD with a locking center diff. only the turbos.

 

Interesting. Frankly, I wouldn't put it past the computer at the junkyard with the pulled tranny to be wrong; it wouldn't be the first time.

 

many standard EA82s had part-time 4WD Dual-Range trannies with just the hi-lo lever, that also selects FWD. the linkage from one of these can be used on a RX trans.

 

That's what I needed to know. Thanks!

 

some Ea82s had part-time 4WD with single range. these had a button on the top of the 5-speed shifter to engage the rear end. this button controls solenoids identical to the RX diff lock one.

 

I don't have shifter linkages on the pulled tranny, but it does at least have provisions in the usual spots for them - the push-pull 4WD engagement comes right off the rear next to where the gear shifter linkage would bolt up.

 

neither of these are a "diff lock", they are fully locked when engaged, but no diff, the other 2 wheels are just completely disengaged and coast.

 

Understood. I was specifically looking for a gearbox with the locking centre diff because I wanted the option of AWD - but I realise that's not the same as a front or rear differential lock used to selectively spool and unspool that particular diff for more traction.

 

I suspect the "diff lock" trans you have is a single range PT4WD trans, and the other is a dual-range PT4WD.

 

I'm kinda leaning towards them both being D/R PT4WD boxes, personally. Is there any good way to identify from outside which box it is?

[Numbchux]

well, if it has the push-pull lever next to the 5-speed shifter, than it's dual-range.

 

a single-range one won't have that push-pull linkage, but will have a vacuum diaphragm near the bellhousing, with a cable running back to the rear of the trans.

 

an RX FT4WD D/R will have both.

 

 

 

and yes, any turbo trans will have 25 splines. and non-turbo EA82s and all EA81s have 23.

[casm]

well, if it has the push-pull lever next to the 5-speed shifter, than it's dual-range.

 

a single-range one won't have that push-pull linkage, but will have a vacuum diaphragm near the bellhousing, with a cable running back to the rear of the trans.

 

an RX FT4WD D/R will have both.

 

From this description, it sounds like the pulled tranny is a standard EA-82 5MT D/R, no centre difflock. I'll double-check on Monday, but I don't recall a vacuum diaphragm on it. Mind you, it is a junkyard pull, so the small stuff it may need to actually make it useful likely isn't anywhere near it.

 

and yes, any turbo trans will have 25 splines. and non-turbo EA82s and all EA81s have 23.

 

I'll count to confirm. Thanks for clearing this up for me!