Looking to do a 727 (update:or 999) swap. Is this the right one?

[TEagle85]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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

[carnuck]

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