88RxTuner Posted July 22, 2008 Share Posted July 22, 2008 I have been wondering for some time how my RX would do with no front axles, and the Center Diff Locked... I got the opportunity today, I blew the right front CV apart while wheeling and dont currently have the funds or motivation to replace an axle... that will come next week, with the paycheck. So, to keep it mobile, I took the ft axles out, removed the outer stubs from the axles, installed the stubs in the hubs to keep the bearings happy, locked it in and took it out for a test drive... WWOOOOOWWWWWIIIIIIIEEEEEEEEEE!!!!!!!!! Holy Smokes, this thing rocks!! With RWD and LSD and nice soft front suspension, drifting around on or off road in rear wheel drive has taken a little bit of getting used to, but it's a lot of fun! Just stomp the gas, wait for the turbo to spool, crank the wheel around a little, and hang the F**ooey on! I know, this defeats the point of Subaru's AWD/4WD powertrain, but just hang on, all you flamers... I'm putting the axles back in next week. In the mean time, I'm gonna see how the transmission handles it... Reports to follow. 88RXTuner Quote Link to comment Share on other sites More sharing options...
88RxTuner Posted August 19, 2008 Author Share Posted August 19, 2008 Well, it's been a few weeks... I've been driving the RX around in rear wheel drive with the diff locked since I grenaded the front axle, and I have to say, it has been more fun than I thought It would. Originally, I had planned to have front axles back in it by the next week... unfortunately radiator hoses, tstat, rad. cap, etc. became an immediate priority, so I had a little longer to test the RWD 5mt theory. First, my fuel economy over the last 3 weeks has gone from about 24.7 mpg average to about 16.1mpg average..TOOO MUCH FUN with the skinny pedal!! I did cruise about 270 miles and averaged 29.3mpg (give or take a little) with no axles in the front... which is an improvement of almost 3mpg over my AWD hiway average mpg of 26.9mpg. So, a slight loss of weight, drag, etc. on the drivetrain creates a fairly significant increase of economy... Of course, this was averaged over under 300 mi, and is not by any means a true average I guess, with only one tank of fuel through it on the hiway... Second, I have had no problems so far, my rear diff. consistently hooks up and locks in even if just powering out of a stop sign. So far, no issues with the transmission at all, I've kept it locked in for 3 weeks and it doesnt show any signs of binding, no noise, etc... all is good. I've come to the conclusion that the weak point in running the AWD5mtDR in RWD only is going to be the rear axles. I just dont think they are going to hold up to the abuse, long term.. so far so good, but they are starting to make noise at me... lol clickety-pop-clunk-BANG-SCREEEECHHHH of tires... something like that. I'm thinking the noise may be failing U-Joints, but I cant help but think the little skinny rear axles are taking all the abuse of 6700rpm launches... and not liking it at all. Anyway, I said there'd be updates, so here it is after almost a month of abuse, and I mean ABUSE!! I'll be the first to admit, I beat the ever-loving SNOT out of this car.. donuts, burnouts, 7Krpm clutch drops, etc.. the whole shebang, on a regular basis... The trans seems to holds up fine, the rear end seems to be doing very well, I'm thinking the axles are the weak link. I'm just using wagon axles in the rear... I'm surprised they lasted THIS long!!! Cant wait to break something so I can report on it.. not that there are a lot of you out there running RWD setups on the EA82 cars. Peace, guys and gals!! 88RXtuner Quote Link to comment Share on other sites More sharing options...
Numbchux Posted August 19, 2008 Share Posted August 19, 2008 people have destroyed the rear output on them. couple on lifted rigs with a second transfer case, and I've heard of people destroying the FT4WD trannies doing the same thing you are. be careful, that center diff isn't bulletproof, and from the reports I've heard, won't show signs until it's too late that said, I've put many thousands of miles on my RX trans in 2WD. mostly FWD due to driveshaft issues (initially it was the lack of a decent carrier bearing mount, lately it's been due to failing u-joints). EDIT: found the passage I was thinking of: "A month of smokey burnouts, drifting, and overwhelming awesomeness came shattering to a halt, when the gears engaging the rear output shaft shredded themselves. (yes, we did open up the case to see exactly what went wrong) No, danbob is no longer RWD." Quote Link to comment Share on other sites More sharing options...
Yo'J Posted August 19, 2008 Share Posted August 19, 2008 EDIT: found the passage I was thinking of: "A month of smokey burnouts, drifting, and overwhelming awesomeness came shattering to a halt, when the gears engaging the rear output shaft shredded themselves. (yes, we did open up the case to see exactly what went wrong) No, danbob is no longer RWD." I love good literature! Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted August 19, 2008 Share Posted August 19, 2008 You could view my thread from earlier: http://www.ultimatesubaru.org/forum/showthread.php?t=81477 Those toothless wonders would be the output gears people have mentioned. These cars are addictingly good at donuts in RWD. A lot of cars will "walk" as you spin, but the subies stay centered over the front end. As you discover the power of the front E-brake to keep the car from speeding up, you will be able to do long distance fishtailing, huge smokeshows and whatnot. Takes some right arm strenght to hold the brakes on as the tires heat up, be warned. I've killed 2 d/r transmissions doing what you are, but I had an EJ22 feeding the torque in, and 215/75r15's or 235/75r15's fighting to hook up on the output end. Had a third tranny die the sameway doing deep snow trailbreaking. #1 killer of these transmissions is wheelhop. Do not try and power out of wheelhop, that's when the teeth come off the gears. I found that the rear axles will click and grind for a long time under abuse but the differentials will fail and the driveshaft u-joints will fail. Broke a stub shaft on the rear diff once too. So, use the handbrake to keep speed in check and the rpm's up, don't do clutch dumps, and avoid wheel hop like the plauge. Quote Link to comment Share on other sites More sharing options...
88RxTuner Posted August 20, 2008 Author Share Posted August 20, 2008 Thanks for the tip about wheel hop. I've noticed it has the tendancy to start hopping when coming out of a burnout, and I try my best stop it, just because I figured it would be hard on the drivetrain. Grabbed a look at the pic on "why you dont beat on a RWD subie.." *car thanks me for not powering out of wheel hop...* that's cool stuff. *beats self up* I'm going to stop dumping the clutch now... Also, I'm still on 185/75s and 13" wheels. I figured it would be less strain on the drivetrain and still allow me to drift around and perform impressive burnouts and snakes. I've already got the park brake thing down, that was my first experiment when I went RWD... SOOOOOOO much fun, get lots of funny looks... ("That 20 year old POS is doing WHAT??")*evil giggle* Are those gears interchangeable between the D/R and S/R? I have access to a number of S/R 4WD, and only 1 spare D/R AWD... that I'd rather not have to use. It'd be nice to know they are an easy find. Also, what goes in the rear diff? I thought these LSD 3.7s were one of the strongest gearsets there are for these? (correct me if I'm wrong.) As someone else pointed out in "why you dont...", destructive testing is quite fun. Hopefully I'll be able to get some pics up. >>"A month of smokey burnouts, drifting, and overwhelming awesomeness came shattering to a halt, when the gears engaging the rear output shaft shredded themselves. (yes, we did open up the case to see exactly what went wrong) No, danbob is no longer RWD." << taken to heart!! Wait, I'm just at a month!! AAHHH!! lol Thanks again for the input, guys!! 88RXTuner Quote Link to comment Share on other sites More sharing options...
88RxTuner Posted October 4, 2008 Author Share Posted October 4, 2008 Okay, guys... it finally happened. I grenaded the trans. BUT, unlike the horror stories about the transfer gears at the back of the trans, 2nd gear came apart. No warning, no whining or noise, and full of oil... I grabbed 2nd coming out of a parking lot, on a right turn, and didnt even get to hit the gas before "BANGBANGscreeee-grinding noise..." First worked fine, 3rd,4th and 5th were fine.. I suspect I sheared the teeth off 2nd gear. That lasted about 2 blocks, as I had to at least get it back to my driveway, and then something else bound up and locked the trans in 1st gear. Thankfully, I have a spare transmission that one of our fantastic members from the Bay Area (Thanks again, by the way..) sold me some time ago.. we'll be getting around to that this weekend. I'm thinking I might actually spring for the front axles too, seeing as being rwd severely hinders my off-road ability... it was fun while it lasted, though!! Now I know, though, and when next year's local RallyX comes up, I'm entering both AWD and RWD classes!! hehehehehe 88RxTuner Quote Link to comment Share on other sites More sharing options...
4x4_Welder Posted October 4, 2008 Share Posted October 4, 2008 It sounds like you just broke the shift rod, and the noise would have been a partial engagement. I had a Toyota trans do this to me. The first failure point of the rear diff is the forward mount and the rear u-joint. The axles are fairly stout for the weight of the car, and traction available. I have pulled those mounts and filled in the spaces in the rubber with black RTV with very good results. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted October 5, 2008 Share Posted October 5, 2008 i went out to montana and back in an 87 rx with the center diff locked. we had a bad wheel bearingf so we swapped on an xt6 trailing arm and were running the passenger rear wheel as a 5 lug and the rest as 4. we removed a rear axle to keep the lsd from burning up (different tire sizes) and locked the diff to run FWD. no problems, but all of our torque was thru the front diff, and we were just highway driving Quote Link to comment Share on other sites More sharing options...
ManYaiK Posted October 5, 2008 Share Posted October 5, 2008 Okay, guys... it finally happened. I grenaded the trans. BUT, unlike the horror stories about the transfer gears at the back of the trans, 2nd gear came apart. No warning, no whining or noise, and full of oil... I grabbed 2nd coming out of a parking lot, on a right turn, and didnt even get to hit the gas before "BANGBANGscreeee-grinding noise..." First worked fine, 3rd,4th and 5th were fine.. I suspect I sheared the teeth off 2nd gear. That lasted about 2 blocks, as I had to at least get it back to my driveway, and then something else bound up and locked the trans in 1st gear......88RxTuner Had the same thing happen to me, but was running 2wd at the time. I was running rwd for awhile with that tranny, didn't have anuff power to be fun on pavement. 90hp SPFI. Was a BLAST on dirt for shure! Now I've got a FT/4WD with an EJ22. Quote Link to comment Share on other sites More sharing options...
baccaruda Posted November 12, 2008 Share Posted November 12, 2008 My car is an 86 wagon with an EJ22, RX trans/LSD, lift, and Legacy 5-lug conversion. I'm in the middle of a "front axle situation" and have basically the same RWD setup as you but with 27" tires. I'm not even taking my car on the freeway. The RX transmission is too rare to risk destroying or damaging. It's not like you can grab one of them any weekend at the junkyard. I respectfully suggest that if you want to continue enjoying your Subaru with RWD that you swap in a standard 3.9 dual range. As long as you keep it in either low or high 4WD it'll feel exactly the same as what you're used to. As a bonus, if you want to put front axles back in (with 23-spline cups of course) you can easily convert the rear LSD to a more aggressive 3.9 ratio. Please don't blow up any more RX trannies. Quote Link to comment Share on other sites More sharing options...
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