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Aegis

Transmission Swap

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So, as a quick small update, I have pulled the torque converter off and separated the bell housing and pump from the transmission. I split those, and to my amazement, the vanes for the oil pump are all present and accounted for. The internals I could see of the transmission did not seem as though to be damaged from a rogue vane being chewed through them. That was a small bit of relief. I am now trying to source the seals, o-rings, and filter/screens before I put the transmission back in. I also still need to swap out the flex plate, hopefully that won't be anything too wild.

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Update - Bad news day...

 

When I went to line up and check the torque converter to get it all installed today I noticed it looked like the rotor inside was broken. Indeed. I had broken the rotor reassembling the pump, I guess. I'm not sure what caused this. I then, turning to the only other pump set I had on hand tried to remove the pump from the bad transmission. Upon disassembling it from the bellhousing to see that it was okay, I put it back together and have proceeded to break the rotor in it too.

 

HOW?! I get that clamping force of bolts are strong but I was using a torque wrench set for 13 ft. lbs. I am beyond stumped and frustrated. I have NO IDEA where to source just another rotor. I guess I am going to call the local transmission shop and see about having them just rebuild the thing right and know that I have good seals and that things are good to go. It is just frustrating that I am going to have to dump another chunk more than I paid for the whole damn truck into it again.

 

Learning experiences...yeesh! I just wish I knew what was putting the rotor under so much stress from barely tightening the bolts. Everything felt and looked lined up. The factory service manual was vague, beyond instructions to mind the orientation of the rotor, but nothing as far as a hint on what that orientation was. I did make sure that I did not flip it when I removed it, so I have no idea.

 

If anyone has any advice for re-assembling the damn thing, and/or maybe where to get a rotor I'd be eternally grateful. Thanks!

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Damn, that sucks! I don't know the insides of these well enough to know what could be going wrong in there. Doesn't seem like the rotor should see any force when you're bolting up the pump, much less enough to break it. Are there any witness marks on the busted rotors for where they hit something? Maybe a bolt got mixed up to the wrong hole and is extending too far, fouling on the rotor somewhere? Compare the bad trans vs the one that keeps eating rotors, see if there's anything obviously different that might be making the pump go on cockeyed or something.

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I've got the pump pulled apart in the office floor currently...

 

The only thing I see which could have been an issue is that the top half of the pump (I'm calling the side that the rotor, wiper/actuator arm, and pins slot into the bottom) has a square portion cast into it around where the shaft passes through the center that looks like it interfaces with the inside of the rotor. The top half looks like some of that square metal casting has chipped off. I guess I didn't manage to line the rotor up well enough and caused it to break the rotor and some of that interface. If that was not the case, my only other option as a point of failure looks like the metal ring that slots into the backside of the 'outer ring' portion that the rotor sits inside of. I don't know the proper name for this, the parts diagram shows it with the rotor as unorderable and doesn't include it with a name or part number at all.

 

I did manage to locate a rotor on a website for G-COR Automotive in Ohio, I think, for $48.00 shipped. It ended up being the wrong rotor as I order without triple checking the design of the broken one. Every website lists them simply as "RE4R01A" rotor with little help between year/design change so I'll have to get back to the search. Just my luck, it seems.

 

If I ever figure this out I'll keep updating for the benefit of anyone else fumbling their way through this as I am.

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Posted (edited)

Something I am looking into now, as my 3.0 does not need the addition front speed sensor the 3.3 SC / 3.5 uses, is if the differing oil pumps without the sensor could work. They seem to be a bit more abundant. If anyone knows the differences in oil pumps or how to tell which had 2 lugs instead of milled flat, this would be useful as well.

 

Update: After grabbing the broken pump set from the original 'bad' transmission and comparing, I'm not sure if a different pump will work. The differ in design, obviously, but the input shaft is also different. The odd thing is that my original 'bad' transmission is using the 2 lug rotor rather than the milled flat rotor of the 'HD' variant transmission I bought as a replacement. This is turned into such a fiasco. The only new pump, which I *think* is the correct pump (R73500AC or U73500AC) ((And who's part number THAT is I have no clue, it's just what all the transmission parts companies seem to use...)) (((On top of that, the part number doesn't even correspond to the RE4R01A... I know my replacement transmission was rebuilt at some point, it seems, but I don't think they swapped pumps, too. I am confused beyond anything right now. I wish there was more information about the tiny changes Nissan/Jatco did in these transmissions and which ones went in which vehicles.)))

Edited by Aegis
Updated

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This thread has lots of pictures of a teardown, probably all stuff you've seen by now of course. Looks like there's some kind of thrust washer endplay spec, though if that was wrong I'd expect it to clamp the rotor and bind it up, not straight-up break it. There was something about a ridge, maybe that could be catching something and holding it cockeyed during assembly? There's also a link at the end to this thread, which is a fairly deep dive into the RE4R01A, though it's for a Skyline.

 

All I know is that I'm very tempted to manual-swap mine if/when my autotragic gives up.

 

Good luck!

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Another update- this time some better news...

 

I have no idea what broke the rotors, still, but I did figure out that the torque converter drives the transmission oil pump rotor. This is probably common knowledge to some, but was helpful for me. The snout on the torque converter is very helpful to determine which style of rotor (2-lug or milled flat) the transmission should have inside. The snout of the 2-lug converter has two grooves in it, whereas the milled flat converter has two flat spots. This determination made it easier for me with the meat of this update...

 

I drove after work on Tuesday afternoon from West Atlanta up to St. Louis and stayed the night for a quick trip up to Springfield (Illinois). I found a 2WD Xterra (with VG33ER - Supercharged variant of the 3.3L) transmission that was only $99! I called and had them confirm it all before making the trip and about 1,500 miles of driving in two days later, I made it back last night with the transmission. The big deal was making sure it had the correct converter and input shaft like my Frontier transmission I was swapping in did. The other big deal is for my dumb@$$ NOT to pull the pump apart and break another rotor. I have fiddled some this morning and extracted the pump and tossed the broken pump into the 2WD transmission. I am going to call a local shop that specializes in the Nissan Z cars to see if it would be any use for them.

 

I will next put the pump from the 2WD transmission into the 4WD transmission and try to get it into the truck soon. So far all looks the exact same and should work out. I guess we'll keep our fingers crossed. I will have to measure a lot before I get under there and wrestle with it.

 

After this whole ordeal is finished, I hope to write up a big chunk of information on these transmissions, from my layman's perspective, with some photos of the differences (HD vs Non-HD, etc...) and to hopefully help both myself and anyone else in the future digging for info on these trucks where the service manuals fall short.

 

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I finally have the transmission and transfer case back in. The old man came up and helped me wrestle it back in yesterday and we got a lot done in about 8 hours of work. I still need to re-install the torsion bars, exhaust y-pipe, and drive shafts. I held off just to test in case I have to rip it back out. So far everything is trending good, but with a few asterisks there...

 

First, the truck doesn't always start. Sometimes the key turn does nothing, sometimes it clicks, and sometimes it starts. It has me a bit confused. I thought it might be a loose connection at the starter but I've got it tight, it seems.

 

Second, the transmission shifter doesn't exactly line up where it used to on the indicator? Reverse looks like neutral, for example. I think it needs adjusted on the cable.

 

Thirdly, when shifting right after start it is okay. When shifting after it's been running, primarily from reverse back to park, there is a loud grinding sound. I'm not sure what that is, either. I added fluid yesterday and I think it might still be low, I haven't got the truck level and in a place to check it, but going by volume it should be close, maybe a few quarts low. I've never seen that cause grinding, though, only failure to shift.

 

Aside from all of this, and my cooler line leaking, it seems to be good to go. I do need to double check my flow and be sure I'm not running the cooler backwards.

 

The install went fairly well. Some bolts are a PITA to reach, wires have to be routed and tucked, vent hose needed to be extended, and it was a bit of a joke to get the truck high enough to get the transmission underneath on the jack, but I'm pretty happy with progress so far.

 

If anyone has any suggestions for the intermittent starting or transmission grinding, I'd love some input.

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#1, could be a worn starter, could be crap connections. I'd try hotwiring it (wire straight from the battery terminal on the starter to the spade to the ignition switch) and see how it likes that. If it's still janky, and it's not the wiring, that leaves the starter; if it's fine like that, it might be the ignition switch (which is surprisingly easy to replace). You might also try tightening up the female side of that spade connector on the off chance it's just loose.

 

#2, yeah, hopefully just a cable adjustment thing.

 

#3, if you've got no driveshaft in it, you're spinning up the transmission's innards and then throwing it into park. That's like putting it in park while the truck's still moving. I'd be surprised if it didn't make bad noises.

 

You did flush or replace the cooler since pulling the old dead trans, right? Don't want to get chunks of dead trans inside your good one. An external filter's not a bad idea either, I've got a Magnefine on mine to hopefully capture whatever wear material was left after my trans flush.

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For the cable there is an adjustment procedure in the fsm. It involves the turnbuckle under the console.There is also one for the range sensor on the side of the trans.
 

Don't put it drive without the driveshafts haha. That’s why it is making that noise.

 

For the starting, there is a common issue on auto pathys where the wiring can’t deliver the full voltage to the solenoid. You can fix this by adding a relay, Mr Reverse had a how to on it somewhere.

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Thanks for the replies!

 

The lack of driveshaft causing the grinding issue occured to me this morning after a night of sleep. I definitely did not do much of that yesterday as it hurt my soul to hear, and I won't be doing it again. 

 

I don't think the old transmission died, so much as had an electrical failure. I plan to really tear into it once I get the truck going and find some free time. To be safe I did flush it, and I do think adding an online filter is not a bad idea as cheap insurance. I'll have to pick up one before I run things much again.

 

The starter is still being a hit or miss issue. I'll definitely look into the relay wiring write-up. I know getting the relay harness for my headlights helped, so I'd believe it'd be good for the starter, too.

 

I'll have to check the service manual for adjusting the shifter, I guess that there was a slight difference between the new and old selector position.

 

By far my biggest regret was having to pull the torsion bars. I am going to have a great time readjusting those. I've seen a few good write ups here, and the service manual seems to have a decent outline of it.

 

Again, my biggest thanks to you lot for helping me with information. It's been emotional, but great, getting to get my truck running again.

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Good to hear it's going again! :aok:

 

The T-bars can be a bit of a pain. Adjust them a little at a time once you're in the ballpark, it's easy to over/undershoot because the suspension settles a little (set, drive, check, reset). I kept a log going of which adjuster I moved how much, and what measurement that gave, which served as a sanity check if nothing else. Make sure you have jackstands under the frame while adjusting the bars, I don't think it's common but IIRC somebody on the FB page stripped the adjuster and just about dropped the truck on himself.

 

When a friend and I dropped the bars out of his S10, we spray painted the adjusters on both sides to mark where they were before so we could put them back in the same place afterwards. Saved us a whole lot of trouble. Little late for yours, though!

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Yes, I did a relay mod to my 93 many years ago when the 3rd starter was acting up right after installing. I did some checking and found I was getting only about 9v to the starter solenoid. I looked at the wiring diagram and decided installing a starter relay like Nissan did for the manual transmission was going to be the easiest solution. It worked great for 15 years. Last year I installed a push button keyless ignition and that is when I found that the problem in my case was simply a worn out ignition switch. I don't have one in there anymore or even the lock, but still have the relay. It is just being triggered by the keyless ignition module now. 

Pretty sure that is what is going on with yours. The oil soaking into the starter is not helpful either. With my original engine I solved that issue with a remote mounted oil filter kit. Current engine is a VG33 with the filter on the front under the alternator, a much better location than the stupid idea of putting it between the exhaust manifold and the starter. 

 

The trans issues have been addressed. 

 

As has been said, when you install the torsion bars, have the weight off the front wheels while adjusting them. Not only is it safer and easier on the threads in the nuts and bolts, but easier to turn said nuts and bolts. Pay close attention to the bars and install them facing the correct way and correct sides. I can't recall exactly but I believe they are marked on the front end for left and right. Your repair manual should have that information. I have heard of and seen t-bars break because they were installed wrong. I believe there is a warning about that in the manual as well, but it has been so long and my mind is a bit fuzzy. 

 

If you can't find the info on the starter relay mod, I believe I still have a diagram stashed in a hard drive for it and I can email it to you. Just let me know and I will chase it down and send it if you like. Just not online as much lately, not enough hours in a day anymore.

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Great advice from everyone, many thanks once again!

 

I got the rear driveshaft installed, piece of cake. Torsions bars... Passenger side was great. Driver side did not fully seat in the front, or something?, and ended up slipping in the splines and nearly cost me what sanity I have left. I do not know what I did wrong, had the truck up on stands with the lower control arm jacked as per the manual. All went mostly okay, I think that maybe the snap ring at the back of the bar slipped through the hole or that I was measuring wrong, I was going with factory specs on the measurements. My impact got the bolts where they were suggested, but it was a bit of a butt-clench deal. I had to file the splines on both the bar and the front anchor, but it all fit back together and now holds the weight of the truck. Time will tell how it holds up once I get it rolling. It almost seems like it can slide too far rearward in the rear anchor and allow it to slip too far out of the front anchor which is why it turned loose. I won't know how this goes until I get the truck running.

 

That leads on to the next part... Once I got the bars in and the truck sitting on it's wheels, I cranked it after the starter decided to co-operate and let it warm up. I then tried to go through the gear, the gear indicator at the shifter still incorrect. It seems to rev and 'bog' accordingly with respect to each gear. It does not pull in reverse, so far. I am going to go out today and start with step one of fixing the control linkage and then moving on to testing the pressure to see if the pump is providing the higher pressure. I will also test to see if the forwards gears work. I was unable to really test last night due to the truck facing the garage and not being able to reverse away. It felt like it was pulling, but it is hard to say. The fluid level seemed fine but I will go over that again once I have tugged the truck back onto a more level spot in the driveway. It sits fairly level where it is now, but pulling it back should let me et a 100% certain answer on the fluid level and test the forward gears again.

 

As for the starter, I'm going to have a search for the relay diagram once I get this buttoned up or determine it is above my pay grade. I did the headlight relay mod a long time ago, so I know that it is definitely a worthwhile way to get more power where it needs to be. I might check the voltage at the starter later today while I am under the truck with the linkage adjustment.

 

Again, thanks to all who have contributed. I have yet to find another forum as friendly as this one has been. The old coots over at the Honda Fit forum are close but you guys definitely deserve a beer/coffee!

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I have now checked the fluid level... Somehow, even after not adding that much fluid (~7 quarts) it is little high, but installing the pressure tester caused some to drain out. The pressure test shows basically no pressure. I'm going to have to double check this after I figure out if I have the correct sized fitting to screw into the transmission. I am going off eyeball measuring but it doesn't screw it super easy. It doesn't require a ton of force, though, either. I'll have a search around to see what I find out about the official Nissan tool size vs what I am current trying to use. It doesn't leak with the fitting installed or during the test, so I assume it isn't a problem. The gauge could be DOA, but it does move a bit. The reverse port shows less than 10PSI. Hmmm...

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