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-   -   Screwy Transmission (My R-154 Rebuild) (http://www.toyota-supra.info/forums/mkiii-supra/21275-screwy-transmission-my-r-154-rebuild.html)

Bru 05-13-2014 01:50 AM

Screwy Transmission (My R-154 Rebuild)
 
5 Attachment(s)
I finally got around to rebuilding the R-154 transmission and was surprised to find something hiding inside the case on the reverse gear pivot bracket. Somehow a Philips screw found its way into the transmission and was hiding harmlessly there. It could definitely done some damage had it been able to circulate. The reason I did the rebuild was because 1st and 2nd are hard to get into when cold. I got a rebuild kit from Drift Motion including a Martin Crawler billet bearing retainer plate and a MC plastic shifter tip. A MC shifter bushing won't work with a C's short shifter, unfortunately. Getting the case off is where nobody has any problems. It's when you start pulling bearings that you definitely need some tools. I have a 12 ton press from Harbor Freight and had some custom press holders made up similar to ones I saw on line. 4 inch 1/4 thick inch angle iron with a strap welded across the top. Mine were 12 inches tall but I think I should've made them 10 to 11 inches using a 12 ton press. I ended up using the tool upside down and on its side C clamped to the press table. A 20 ton press would probably have been a better choice. Pulling the rear support bearing requires a large three jaw puller. Getting it back on later, I used a 18 inch piece of 1 1/4 inch diameter pipe. The inside diameter is just right for the inner race and I used it to drive on the center support bearing also. Alro steel is where I got the steel cut. Total cost was $36 and $20 to get the straps welded on top (with a slight overhang) at a mulffler shop. For the input bearing installation I made a copy of the special service tool using a 1 1/4 inch threaded pipe flange. I ground the threads away with a drill and a round stone to make the hole 1.6 inches diameter. On top, under the press, I used a piece of 1/2 inch scrap steel that I got from the scrap box at Alro for free. I did not have a bearing splitter for the end bearing on the counter shaft so I used an angle grinder to cut slots on opposite sides of the bearing and my custom tool to hold it by the slots with a smaller than the shaft socket on top to push the shaft out. Use a 24mm socket to drive the new bearing in. Some of those bearings, hubs, gears come loose with a bang! Be sure the hub keys are in the syncro slots made for them. I made the mistake of testing first gear by sliding the hub sleeve over without first putting the C clips that stop the shaft. It went too far and the hub keys fell out! It was a lot of unnecessary trouble to get it back into order since the the gears were already pressed onto the shaft. The shift interlock has 2 balls, 2 thick pins, and 2 thin pins. Just follow the Toyota manual and you won't go wrong. One ball goes in that reverse/5th gear bracket behind the shift plate. The other ball is at the bottom of the shift plate hole. The thin pins go in shafts. The thick pins go between the shafts in the shift plate. The Torx bit needed for the 4 caps is a T-40. I was able to get 94 ft/lbs torque on the counter gear stake nut with the shift plate clamped in a vice on the floor. I came up 10 ft/lbs at a time until I got it there. The 5th gear came off using a steering wheel puller. During the disassembly I checked the clearances with feeler gauges and a dial indicator to see if something was out of specification. Turns out nothing was. The input shaft bearing was a little wobbly but there's no measurement to check that. I replaced the first and second gear roller bearings, just in case. They are not pressed in. They fall right out. The oil clearance on the old ones were in spec (using a dial indicator moving the gear up and down on the shaft). I replaced the first gear shift fork with a stock one. Torqure the fork bolts to 14 ft/lbs with blue thread locker, no more. Its only aluminum and could crack. I replaced the first gear thrust washer after hearing so many horror stories. Turns out it was like new and measured the same thickness as the new one (stock horse power). Looking back maybe I could have replaced the first gear hub sleeve and even the first gear hub but that would cost another $190. I looked for burs and cleaned them up with a small file. I won't know the true results until I get the engine back together for a road test. I'll be using the redline MT-90 oil that Drift Motion recommends with their kit.
Check out the Web site where they rebuilt a transmission similar to the R-154. The link to the second page is at the bottom of the frist.

http://www.4wdmechanix.com/Moses-Lud...nspection.html

Something worth mentioning. The 3rd / 4th gear hub sleeve, like the hub, goes in a specific direction.
The picture in the Toyota manual is clear about the hub. The sleeve is more subtle. If you look carefully
at the drawing the sleeve has a chamfer that faces front also. Actually, there is a groove cut into it.
The photos at the website makes it clear. I was able to check mine after assembly by taking off the bell housing and front bearings retainer cover. There is a oil hole through the housing that allowed me to visually check it. I also had a dental mirror and a small flash light to check the back side. I'm very releaved that it was on the right way. It would have been a lot of additional work just to filp it over.
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I got the engine and transmission back together. After a week of driving, I can say that its shifting better, espcially down shifting into 2nd while turning a corner. R154s were never a smooth shifting transmission to begin with and are notcy by nature. Getting into 1st gear is better but I wonder if replacing the hub and sleeve would have made any differance.


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