Author Topic: Looking to do a 727 (update:or 999) swap. Is this the right one? (Read 10444 times)

TEagle85 · « **on:** December 04, 2015, 05:19:03 PM »

Found Transmission out of a 88 grand wagoneer. 5.9l 4x4 3.31 ratio on the axles.

Should I pick this up.? Seems to be the sought after one. would it be fine with my stock 4.2l?
Want to jump on this quick so any info helps.

85 eagle sedan
258
not sure current trans or TC but 2.35 ratio.
plan to eventually swap the gears as soon as I find a front diff thats not a 2.35 and the TC will be swapped.

I should also say the TC and Diffs will go in at the same time

Thanks

eaglefreek · « **Reply #1 on:** December 04, 2015, 06:18:48 PM »

Yes, it's a bolt in. You'll need the torque converter, also. Not sure about the flexplate. I personally don't think the 727 is a good choice for an Eagle because it takes more horsepower since the internals are heavier, but others have done the swap and were happy with it.

TEagle85 · « **Reply #2 on:** December 04, 2015, 06:26:27 PM »

I'm still doing some debating but since its available I was going to jump on it. In the end I really only want 3.08 gearing and a different TC with low range. With the stock Trans that should be enough for me, maybe ha?
I just like giving the car a little heck on the dirt roads. Not trying to Rock crawl. I think more rally then crawling. But would like the confidence of a bullet proof set up.

amcfool1 · « **Reply #3 on:** December 05, 2015, 03:57:11 AM »

hi, a 727 is a very good trans, and WILL work in an Eagle, however, it is a bolt in , but not a "simple" bolt in, (what is!...) It is physically larger, so some floorpan tweaking may be in order, as well as driveshaft shortening/rebalancing. shifter tweaking, etc. In other words, it'a JOB 'o Work! If that is fine with you, go for it! On the other hand...there's a fist! Joking! Anyway, on the other hand, your 998 can be rebuilt to 999 specs, making it stronger, and next to bulletproof., with no fitment issues. Also, I believe your car has it's original 258. A 727 sucks up about 40 hp. a 998/999 about 20, (I'm estimating here), So, unless you seriously hop up your 258, a 727 will seriously slow you down. There's a reason they put 727's behind large V8's, and the 904/998/999 family behind sixes and small V8's, the AMC 304 V8 used the 998. Only the 360/401 used the 727. Yes, the 727 behind your 258 WILL be bulletproof, but that's mostly because your 258 is too weak to kill it. Your stock 998 is a VERY good transmission,and hard to kill in stock form. I have over 300,000 miles on my Eagle #1 998 with one rebuild 15 years ago. There are ways to beef up the 904/998 family of transmissions, for racing, offroad, whatever, I suggest you try that first, then when, and IF...IF, you manage to break a 998, go to a 727. Remember, AMC engineers were the best in the business , they did the most with the least. Be very sure of what you are doing before you try to re-engineer the car. good luck. gz
ps, I have come to this conclusion after MANY years of watching guys "improve" their cars so that they never run again!, or at least not well, and definitely not reliably.

TEagle85 · « **Reply #4 on:** December 05, 2015, 08:43:41 AM »

Thanks for that guys, definitely some great food for thought.
Maybe I should focus on getting rid of that 2.35 first then go from there.

The 998 rebuild seems like a better path for me considering I really should focus on using this car more, starred at it sitting in the garage too long already, and I see that car sitting for at least a whole summer before I would figure it out and get that 727 trans in.

So if anyone needs a 727 there is one on ebay right now in MN.

What Ill do is look for a 998 to rebuild and make any mods needed.
Rather rebuild a found one and take my time plus still be able to drive my car seeing how I know that if I pulled and worked on the original the car would be out of duty for months. The search for a 998 begins.

guess I should just find a eagle just to use for parts, ha.
Which would officially make me a Eagle nut I suppose.

eaglefreek · « **Reply #5 on:** December 05, 2015, 09:22:25 AM »

Quote from: amcfool1 on December 05, 2015, 03:57:11 AM

hi, a 727 is a very good trans, and WILL work in an Eagle, however, it is a bolt in , but not a "simple" bolt in, (what is!...) It is physically larger, so some floorpan tweaking may be in order, as well as driveshaft shortening/rebalancing. shifter tweaking, etc. In other words, it'a JOB 'o Work! If that is fine with you, go for it! On the other hand...there's a fist! Joking! Anyway, on the other hand, your 998 can be rebuilt to 999 specs, making it stronger, and next to bulletproof., with no fitment issues. Also, I believe your car has it's original 258. A 727 sucks up about 40 hp. a 998/999 about 20, (I'm estimating here), So, unless you seriously hop up your 258, a 727 will seriously slow you down. There's a reason they put 727's behind large V8's, and the 904/998/999 family behind sixes and small V8's, the AMC 304 V8 used the 998. Only the 360/401 used the 727. Yes, the 727 behind your 258 WILL be bulletproof, but that's mostly because your 258 is too weak to kill it. Your stock 998 is a VERY good transmission,and hard to kill in stock form. I have over 300,000 miles on my Eagle #1 998 with one rebuild 15 years ago. There are ways to beef up the 904/998 family of transmissions, for racing, offroad, whatever, I suggest you try that first, then when, and IF...IF, you manage to break a 998, go to a 727. Remember, AMC engineers were the best in the business , they did the most with the least. Be very sure of what you are doing before you try to re-engineer the car. good luck. gz
ps, I have come to this conclusion after MANY years of watching guys "improve" their cars so that they never run again!, or at least not well, and definitely not reliably.

That's the first I've heard about the transmission being longer and needing driveshaft alteration. As far as I know it's a 1/4" longer at the most. But, I agree with everything else you said. I had my 998 rebuilt to 999 specs with a Transgo shift kit and it was a big improvement. However, after installing an AW4, I'll never go back to a 3 speed auto.

TEagle85 · « **Reply #6 on:** December 05, 2015, 09:35:19 AM »

Well Im open to suggestions on different trans to look for and dont mind a little bit of modification. Just need to find that combo of cost, time, purpose, and part availability.

If a certain swap needs different splined drive shafts and lengths etc. Im probably out unless I had a swap list in hand of all the parts I would need and where to find them. My knowledge of years and models they moved and changed parts for is very limited but Im trying to learn.

I know there is probably plenty of info buried in this forum somewhere so Ill look into the "999" rebuild and the AW4 as other options. Another gear does sounds nice.

eaglefreek · « **Reply #7 on:** December 05, 2015, 12:01:14 PM »

An AW4 swap takes a lot of of fabrication and some wiring. A 998/999 is a fine transmission. I think if you upgrade to 3.08's you'll be happy.

amcfool1 · « **Reply #8 on:** December 06, 2015, 08:48:37 AM »

hi, for a good writeup on a AW4 swap (on a TWO wheel drive car, Eagle will be a little more difficult) go to www.theamcforum.com and look in the "transmission / drivetrain section" gz

TEagle85 · « **Reply #9 on:** December 06, 2015, 01:15:28 PM »

Ill check it out just to get a little taste of whats involved but I think for me the 999 conversion will be fine. So far Ive been fine with 3sp but I know a 4 would be so much better.

Thanks a lot guys.

carnuck · « **Reply #10 on:** December 06, 2015, 02:27:50 PM »

Skipping ahead here, but to save the OP a LOT of frustration, first see which starter the Grand Wagoneer had. Post '87 went to XJ style starter and they changed the torque converter pattern too. The flexplate on the Eagle will have either 1 or 2 bolt patterns (9XX or early 727) and the ring gear won't line up to 1 hole. (they went to equal converter bolt pattern with the XJ style starter change and moved the ring gear 10 mm closer to the motor at the same time )

You can easily wire the XJ style starter in where the Ford style was but it can only be done with the right flexplate. You could have the 360 flexplate zero balanced but you can get a new 6 cyl one, probably for less money.

TEagle85 · « **Reply #11 on:** December 06, 2015, 02:30:22 PM »

http://www.ebay.com/itm/141773721603?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Here is the ebay link if anyone wants to take a looks at it

carnuck · « **Reply #12 on:** December 06, 2015, 02:34:11 PM »

Quote from: eaglefreek on December 05, 2015, 09:22:25 AM

Quote from: amcfool1 on December 05, 2015, 03:57:11 AM
hi, a 727 is a very good trans, and WILL work in an Eagle, however, it is a bolt in , but not a "simple" bolt in, (what is!...) It is physically larger, so some floorpan tweaking may be in order, as well as driveshaft shortening/rebalancing. shifter tweaking, etc. In other words, it'a JOB 'o Work! If that is fine with you, go for it! On the other hand...there's a fist! Joking! Anyway, on the other hand, your 998 can be rebuilt to 999 specs, making it stronger, and next to bulletproof., with no fitment issues. Also, I believe your car has it's original 258. A 727 sucks up about 40 hp. a 998/999 about 20, (I'm estimating here), So, unless you seriously hop up your 258, a 727 will seriously slow you down. There's a reason they put 727's behind large V8's, and the 904/998/999 family behind sixes and small V8's, the AMC 304 V8 used the 998. Only the 360/401 used the 727. Yes, the 727 behind your 258 WILL be bulletproof, but that's mostly because your 258 is too weak to kill it. Your stock 998 is a VERY good transmission,and hard to kill in stock form. I have over 300,000 miles on my Eagle #1 998 with one rebuild 15 years ago. There are ways to beef up the 904/998 family of transmissions, for racing, offroad, whatever, I suggest you try that first, then when, and IF...IF, you manage to break a 998, go to a 727. Remember, AMC engineers were the best in the business , they did the most with the least. Be very sure of what you are doing before you try to re-engineer the car. good luck. gz
ps, I have come to this conclusion after MANY years of watching guys "improve" their cars so that they never run again!, or at least not well, and definitely not reliably.

That's the first I've heard about the transmission being longer and needing driveshaft alteration. As far as I know it's a 1/4" longer at the most. But, I agree with everything else you said. I had my 998 rebuilt to 999 specs with a Transgo shift kit and it was a big improvement. However, after installing an AW4, I'll never go back to a 3 speed auto.

The Jeep 727 4x4 version is same length as the 4x4 version of the 9XX. 4X4 version AW4 is 3.5" longer and you need '91 or newer for 23 spline plus a 1" spacer ring if you use the Eagle or FSJ tcase.

I'm still surprised I never found anyone wanting to buy the 999 case I have from a '99 Wrangler with 4.0L. It's a stronger case than the Eagle one (bolt in rear sprague for one and CPS hole in the bell for EFI conversion)

If you can pick it up, that's a good starting point pricewise but shipping is usually $150+ on those transmissions unless they have someone that ships freight for them.

amcfool1 · « **Reply #13 on:** December 06, 2015, 04:49:59 PM »

hey carnuck, still looking to sell that viscous coupling? gz

carnuck · « **Reply #14 on:** December 06, 2015, 06:48:57 PM »

Yeah. Life has been a little screwed up. Max98059 ruined this past year (especially summer) for me.

TEagle85 · « **Reply #15 on:** February 29, 2016, 07:16:58 PM »

So back with another trans question. working on pulling the current 998 to rebuild and update it as much as possible. Willing to drop a little cash on the rebuild so I don't have to worry about it as much and also get a little more performance. Figure it will be a butt load of my time and after the parts be around $400-500?

Came across this on CL near me, looks pretty fresh. Would it be a bolt on for the 258? I'm pretty sure its a lock up torque converter on my current setup but would be getting a new one anyway so doesn't really matter I guess.

http://chicago.craigslist.org/sox/pts/5470185104.html

Reads: tf999 trans with 1200 miles on it, hd clutches&steels and vent relocated,removed for v8 conversion

Asking $350

Also will note Im rebuilding a 242 T-case to mount to it.

TEagle85 · « **Reply #16 on:** February 29, 2016, 08:14:19 PM »

also emailed to ask what year its from but I think pre 90' is what you need, before they switched to the computer controlled Torque converter

Update, from a 88' so now just need to think is it worth going the used 999 route or for the same amount rebuild my 998. Think Im going to go for it. he also has a tf999 there that has been overbuild with poly bushing, seals etc, with the torque converter for $550.

Will that 88' tf999 bolt to a NP242 fine?

carnuck · « **Reply #17 on:** March 01, 2016, 02:25:33 PM »

Again, they changed the converter to flexplate bolt pattern around '88. If it's a Jeep 4.0L style starter, then the bolt pattern is even and the teeth for the ring gear are 10 mm closer to the motor.

TEagle85 · « **Reply #18 on:** March 01, 2016, 02:42:38 PM »

Thanks carnuck, Ill look into a little more, paying attention to that area. Pulling my trans slowly this week and going to check that 999 out so at least Ill have some reference pictures. I know Im going to learn some lessons on this trans T-case swap but thats probably the best any only way to learn (and blow money).

carnuck · « **Reply #19 on:** March 01, 2016, 02:56:01 PM »

Too bad you're not closer to me. I have a '99 TJ with 4.0L 999 bare case in the pile that is going away. It has the bolt in rear sprague (needed for heavy loads or hill climbing) and coupled with a braze welded billet torque converter neck, it becomes almost bullet proof. As for the NV242, make sure it's 23 spline and not too shallow. '87-90 XJ ones are 21 spline with AW4 or BA 10/5 standard trans.

TEagle85 · « **Reply #20 on:** March 01, 2016, 03:07:15 PM »

Thats one reason Im looking at that 999, non lock up converter and then I can get the braze welded billet torque converter neck (whenever I find it online)
will miss the lock up on the highway but does it really make that much of a difference between the two. Basically your handing off better millage for strength? Higher RPMs on the highway?
Can I put in a bolt in sprag in my current 998, or a 999 or is that a factory thing?

seeing them here for the 727, assuming that will slip into the 998/999?
http://www.jegs.com/i/TCI/890/127000/10002/-1?CAWELAID=1710579318&CAGPSPN=pla&gclid=CJTZ8O2loMsCFQ4zaQod84kKhQ

carnuck · « **Reply #21 on:** March 01, 2016, 05:55:37 PM »

999 comes in lockup and non-lockup version. They make a bolt in for 727, but not sure for the A904 hydraulic lockup version of the trans.

I guess there is! http://www.aandatrans.com/departments/chrysler-727-trans/bolt-in-sprag.aspx

TEagle85 · « **Reply #22 on:** March 02, 2016, 11:13:44 AM »

thanks for the link. Would it matter if it were lock up or not for that bolt in sprag? I dont see it posted anywhere if the bolt in sprag is for a spacific 904/998/999?
Id like to get it for either the 999 non lock I get or if I decide to rebuild my 998 lock up. sorry for side tracking this thread.

carnuck · « **Reply #23 on:** March 04, 2016, 06:49:36 PM »

The sprague is different 727 to 9xx. Aside from that, I don't know of any difference other than maybe 9XX (aka 32RH) to 32RE (999 with electric converter lockup control in the valvebody)

The lockup converter needs the correct valvebody, input shaft and '79 or newer case (with correct passages for fluid pressure)

TEagle85 · « **Reply #24 on:** March 06, 2016, 11:15:13 AM »

update the trans and T-case are out.

With it out and not started on I feel like this is a good time to give myself more of a headache of options.
What would you do?

?

------Either just rebuild my 998 to some decent specs and then rebuild by stock T-case?-----
Saw midwest trans sells remanufactured viscus couplers. Mine feels fine but I think there is chain slop and thats what I noticed on the highway when maintaining speed. Felt like there was slack in the drivetrain like when you let off and accelerated slightly there would be a small jerk. Thats why I decided to pull everything for a rebuild. Pretty sure its a NP119 and I see there is a rebuild kit on ebay. BUT Im not seeing a replacement chain.
So thats option 1, low headache rebuild with all stock stuff.

------Option 2, use this as a opportunity to swap it all. Starting to see a 242 swap will be a pain in the butt. I dont know what to look for and it seems I need someone to just tell me what to buy. I can install anything mechanically but just about to explode with all the fitting issue info out there. Shaft input length and what not. I know its all hidden in the forum but I seriously have spent like 6 hours a day on here and feel like Im not getting anywhere. SO other option is getting a 999 from a 88 or before Jeep. Then use that new 999 interface and shaft to place a new Tcase on there with less fitting headaches. At this point I dont care if its a 242, starting to rule that out. So looking for the next best thing.

What would you do If you had a 85 sedan sitting in your garage with the trans and Tcase pulled and ready to get a drivetrain back. Got cash burning a hole in my pocket but need to keep it between a the 998 or 999 since thats what within my capability.

The one thing I can add is getting the driveshafts lengthened or shortened could maybe be a option since I would just bring it to a shaft shop and have them do it assuming its not like $1000 to do. Or buy new ones but again someone would have to tell me exactly what ones to buy. Drive shaft length I get. The input and output shaft lengths I get but cant explore unless I have them all laid out in front of me. So I ask you.

Someone tell me a trans t-case combo to buy!!!!!

As always appreciate the advice hopefully soon I can give back to this site as much as I have taken from it.

Untitled by T A, on Flickr

amcfool1 · « **Reply #25 on:** March 06, 2016, 12:10:07 PM »

hi, I usually apply the KISS method (Keep It Simple, Stupid!:) and rebuild the stock system. You have it, it's bought and paid for, and you KNOW it will fit and work. Again, I have seen too many cars "improved" so that they never run again. I am not against upgrades/parts swaps per se, but usually only do them only when the original is beyond repair. good luck, gz

TEagle85 · « **Reply #26 on:** March 06, 2016, 01:28:37 PM »

We were always told to use the KISS system in design school and I don't know why I'm not using it now. Just excited at all the possibilities I guess, I will take that advice and I think I will avoid a lot of trouble.
Maybe down the road I can get crazy. Which I still would like to do with this car. Its already unique but Im a tinkerer and just looking for excuses to tinker.

amcfool1 · « **Reply #27 on:** March 06, 2016, 03:10:19 PM »

hey, it's ALL good, tinker away, i do all the time, just finished swapping out the old cast iron intake,exhaust manifolds on my 77 Hornet AMX to the more "modern" 82+ Eagle aluminum intake and separate exhaust manifolds, but again, I did this because the original exhaust manifold, 39 years old, was leaking and had a crack in it. Nothing wrong with tinkering, just make sure the car runs when you're done! good luck, gz

carnuck · « **Reply #28 on:** March 07, 2016, 01:30:44 PM »

You need to swap the front yoke from the original NP"whatever" Eagle tcase to Grand Wagoneer tcase and add a low range lever and re-clock the speedo housing. Also swap the 998 shift and passing gear linkage to the 727. Dipstick tube was the hardest fix.