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998 vs 727 |
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billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
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It's amazing how little AMC folks know of Eagles........... people keep saying "use one out of an Eagle" NO you can't. The case is DIFFERENT because the car is FOUR WHEEL DRIVE and has a TRANSFER CASE that bolts DIRECTLY to the end of the transmission. The case is AMC designed for that purpose. Junk ignition systems? LOL - you hate everything AMC, don't you? it's a FORD system identical to every single car Ford produced in the late 70s and 1980s. I made a living on cars for years - and honestly saw no more AMC or Ford products dragged in due to ignition than I did MOPAR or Chevrolet. They all had their issues back then. It was the early days of electronic conrols. Junk transmission? If that were the case then almost all Chrysler products would be there, too and people would be throwing the MOPAR transmissions away instead of still using them - like I am...... You hate AMCs and yet hang out here - maybe you are here to spread your hate? |
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Mopar_guy
Supporter of TheAMCForum Joined: Jun/07/2009 Location: Ohio Status: Offline Points: 4805 |
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I had the same thought. My guess is that the sprag spun in the case from what he's saying, "It is pretty scored". There's no reason the rebuilder couldn't put a bolt-in sprag in it and save what he has. A good HD convertor is a must - not just some rebuilt unit. |
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"Hemilina" My 1973, 5.7 Hemi swapped Javelin |
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billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
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I want to clarify my earlier messages on Eagle transmissions - they used totally different output shafts and tail housings. You could use the base housing but keep in mind the Eagle used lock-up converters and the tail was totally different.
The tail housing that bolts on is meant for transfer case. The t-case bolts directly to the extension housing of an Eagle transmission. The output shaft is totally different. It splines to a transfer case - directly. The transmission used a lock-up converter. Your car did not Only the front end would be similar and with the lock-up vs. non-lock-up converter, you may run into other differences as well as far as design. You can't use an Eagle transmission directly. The back ends are totally different. The front would be the same as a 2wd car with lock-up converter. So beware - investigate thoroughly before assuming.
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purple72Gremlin
AMC Addicted Charter Member Joined: Jul/01/2007 Location: Illinois Status: Offline Points: 16591 |
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billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
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Some things will vary due to the lock-up converter being used by AMC in the early Eagles - I believe up through 1984. But if you wanted to convert an Eagle transmission to 2wd that should work out.
In other words, I'd not use the Eagle parts for a transmission, I'd use non-Eagle parts to convert the Eagle transmission over. I'll have to dig into my books and my transmissions sitting on a shelf to verify a couple of things but that should be doable. In any case, BOLT that one-way clutch in, don't rely on the splines to hold it into the case. That's the weak spot. There have been many hundreds converted to bolt-in one-way clutches over the years. (a sprag clutch is simply a different design one-way clutch. Instead of round rollers it has odd shaped pieces more like a figure 8. So if the rollers are round like a roller bearing with ramps, it's NOT a sprag. Both are one-way clutches, or over-running clutches, but the sprag is a very specific design. If there are round rollers, it's not a sprag.) |
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1970390amx
AMC Addicted Joined: Jul/11/2008 Location: colorado Status: Offline Points: 3311 |
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The 998 low roller clutch outer race is riveted to the case, no need for bolt in roller clutch. I am sure what the original post is about is that the inner race has dug a round slot were it spins against the rear of the case. All cases are the same as for as lock up or not. The valve body, stator support and input shaft is what changed. An eagle CORE cold have a lot of parts in it that are better than his original trans.
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1970 390 4speed Bittersweet shadow mask AMX
1970 Amx missing most everything, or in a box |
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purple72Gremlin
AMC Addicted Charter Member Joined: Jul/01/2007 Location: Illinois Status: Offline Points: 16591 |
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The 727 is what uses a bolt in sprag. The stock set up is held in by one little Allen screw. That's a weak link in the 727. The 904-998 doesn't have that issue. 1970390AMX is correct.
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WesternRed
AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Offline Points: 5787 |
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Bolt in Sprag for 904:
Sometimes you have to fix stuff, it's not like the old days where you can just go to the wrecking yard and get another one.
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billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
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Yeah, that's right. I had forgotten. However, the 998 doesn't use a sprag, it's a simple overrunning clutch. There's a difference. The overrunning clutch as used in the 998 has round rollers - a sprag uses oddly shaped pieces. People keep calling it a sprag like every adjustable wrench is called a Crescent wrench. The sprag is a specific design - similar but more positive lock. A true sprag doesn't have the round rollers that when you lay them on the bench they roll away onto the floor. Sprag clutch pieces can't roll. So now that that's cleared up............ It's still a design where the overrunning clutch parts can be damaged badly - the rollers can get flattened and the race ramps worn to where it doesn't hold well.
Sprag clutch design is less prone to that, more positive a lock. also more expensive would be my guess. I'll have to dig into one of the Eagle transmissions I have on the shelf because although I know the control is a lockup module on the valve body and the fluid to lock things up goes to the reaction shaft support (part of the pump) the case has to be drilled for that fluid passage. it's not like a BW that has tubes. The VB bolts to the case and the signal goes through the case into the pump and out the reaction shaft support to the converter to lock it up. So although I've not tried this - you could likely use a lockup type case on a non-lockup transmission you can't use a non-lockup transmission case on one with the lockup module and converter - the pressure can't get into the converter without a hole in the case to carry the fluid. Anyway, the Eagle automatics "around here" are typically in WORSE shape than others - at least in our area. They got burned, they got used, people used those cars hard in the winter. I figure around here you have a 50-50 shot or worse at getting a decent transmission out of an Eagle. People used them in the winter and got them stuck, rocked the cars, abused them with BLADES and yes I said blades, mounted on the front. They also pushed around a HEAVY car. I think the SX4 is something like 3200 pounds (and that's a two door with a six) and the wagon heavier. That being said, the case should be ok but the rest maybe not. |
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DaemonForce
AMC Addicted Joined: Jul/05/2012 Location: Olympia, WA Status: Offline Points: 1070 |
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Oh look, this guy knows. I've seen people convert this transmission from 2WD to 4WD on more than one occasion so I'm sure the reverse is possible starting with an Eagle core. The Eagle case is a superior 998 casting but in my luck I have only found BAD cores similar to the OP's problem here. Sprague has never been my issue but the valve body is a headache. Use the Eagle trans case and maybe some internals but mainly use the donor case. That's the entire point of the swap. It's work and still a massive coin flip, usually effected by miles and where you find it, so pay attention. I wouldn't waste any more time with it than I have already but in this case it's either pick up an Eagle core, spend a TON of $$$$ trying to replace it with another inferior 998, play the waiting game or swap in a 727. Tough choice. Not. Come to think of it I've rarely seen these swaps done to the 727 but they still happen. No idea why.
The Ford ignition system is an iron plague. Every AMC owner I've ever met drastically changed their factory ignition system or suffered. Oddly, the engine side of the ignition system hasn't been my problem so much as common failure parts like the OEM SSI module and factory switches. These reveal to be symptoms of much bigger problems, like the control wiring for the dash. That's not a Ford issue, it's all AMC/Jeep poor wiring practices. I didn't even discover this until a month ago and I get to fix it this weekend. Thank God I didn't buy many of the crap female Packard terminals shipped by NAPA. Those are flat out $1/pc overpriced garbage. Brass plated 1599C for the win.
You ever hear the phrase leave it where you found it? Ever crawl under a yard Jeep? Tell me what you see. The Chrysler automatic is the bane of every AMC ever. between the two I'd rather have the early BW auto or literally anything else. I would even consider the TH and I actually hate that thing. I replaced the 998 with a T-5 and haven't looked back. The only possible evolution from here is the AX-15 but I'll never find one.
Wait what? Usually I find early AMCs that didn't have the lockup system until 1984. Somehow my 1983 wagon was the exception to this and it is the only pre-1984 I've ever found to come out of Brampton. Why?
A buddy of mine did the 2WD conversion to his Eagle 998 and scrapped the car to make his Hornet move again. It sounds dumb but I'm sure he had good reasons. It worked out but his Hornet ended up in the scrapyard a year later and I never asked him about it. The Eagle 998 case is resilient but all of mine have been junk. The one I have left doesn't have a home and is rotting away in one of my trailers. |
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1971 Javelin SST
American 304 2v | FMX | AM20-3.31 1983 American Limited Jeep 4(.7)L S-MPFI | 1982 NWC T-5M (4.03/.76) | Dana30IFS/35-2.72 |
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