1985 AMC Eagle wagon build

[The Dark Side of Will]

Boost on a Jeep 4.0: http://www.jeepstrokers.com/forum/viewt ... 285#p13285

Lots of work in the body: back halved AMC Spirit at <2200#
Stock 4.0 and built TF 904 trans. 400 HP/450 TQ on 10 psi with E85. 10.7's best.

I will NOT be doing this with my Eagle... just showing what a 4.0 can do with a little extra manifold pressure.

[The Dark Side of Will]

I snagged an extra transmission not too long after I decided I'd do this. It's another Eagle T5.



I pulled the T-case adapter off it last weekend and counted teeth. It has the 53/23 fifth gear pair. There is a 61/25 fifth pair that is good for a 5.8% taller fifth gear.

I originally thought that the Eagles had 0.81 fifth gears, but my dad's found references to them having 0.76 fifth gears. I guess I'll have to pull the top cover and count input gear teeth to figure it out.
Swapping from the 53/23 to the 61/25 would move 5th from 0.76 to 0.72.
That's probably the widest ratio spread I can have in a T5, however, there are some info pages my dad's found that I haven't had the time to fully examine yet.

http://www.allstategear.com/T5.htm

http://www.mackstrans.com/BorgWarnerT5.html

http://cobratransmission.com/index.php? ... 20a&page=1

Edit: Giant jumble of T5 info:

http://www.allfordmustangs.com/Detailed/349.shtml
http://www.moderndriveline.com/Technica ... n_spec.htm
http://www.moderndriveline.com/Technica ... mec_t5.htm
http://www.drivetrain.com/parts_catalog ... l_kit.html
http://www.flatheadv8.org/t5-swap.htm
http://www.jalopyjournal.com/forum/show ... p?t=169265
http://www.vanpeltsales.com/FH_web/t5_fivespeed.htm
http://www.ttcautomotive.com/English/products/T-5.asp
http://www.britishv8.org/Articles/Borg- ... D-Tags.htm
http://www.adchevy.com/techtips/t5list/
http://www.inliners.org/Jack/t5_page.html

[Nashco]

Tearing into it just to count teeth? I guess you like the mess...? I usually just spin the input and count rotations on the output, pretty easy when you don't have a diff inside the trans (or know for a fact what one of the gear sets is).

Bryce

[The Dark Side of Will]

There are a LOT of different T5 combos. The configurations are well documented for Mustangs, Camaros and to a lesser extent Jeeps. However, the Eagle got the AMC passenger car configuration, which isn't the same as the Jeep configuration and isn't very well documented.

[Atilla the Fun]

There's no way I'll ever run any trans without knowing the ratios more accurately than just 2 decimal places. And sometimes the only way to find out is to count for yourself the number of teeth on every gear.
Ratios do matter.
The 0.76:1 fifth was used in all the '88-'92 V6 Camaro / Firebird T5-WCs, with 4.03 / 2.37 / 1.49 for the lower gears. I've had my hands on one of these, they are a joy to shift. Truly excellent once you get a Steeda Tri-Ax shifter.
It is possible to get the good gearing into the Eagle case, then you can have the 2.952380952 / 1.9375 / 1.336206896 / 1.0 / 0.728030303 ratios. I believe the alternate 0.63:1 fifth is actually 0.625
If you start with the 0.63, then you can get an aftermarket 0.800, or if you start with the 0.73, then you can get an aftermarket 0.59

[The Dark Side of Will]

Actually, now that I know more about T5's, I want the 4.03 first and 0.72 fifth... that's the widest ratio spread I can get and will give me a 37:1 crawl ratio. At 5.597, that's a wider ratio spread than the TR6060 I just bought for Bad Idea BMW at 5.281.

Won't be so sporting on pavement, but it's an Eagle. The most powerful engine it's ever going to get is a stock 4.0 HO at 190/220ish.

[Atilla the Fun]

The TR6060 really isn't any better than the T56 it's based on. The '93 Z28 with the standard 2.73:1 axle had a 3.36:1 first and the 2.07:1 second and a 0.62:1 sixth. The current Shelby Cobra combines a 2.97:1 first with a 1.78:1 second and the 0.50:1 sixth. Surely you can get the T56 to a wider spread than 5.28
With the T5, you can't mix and match the ratios so flexibly. If you want the 0.72:1 fifth, then your deepest first is 3.75:1. If you want the 4.03:1 then you must accept the 0.76:1.
( Any comments on welding my GN ball? )

[The Dark Side of Will]

According to the list of part numbers I've found for the Jeep T5's, they had the 4.03 first with 0.76 fifth using the 53/23 gearset. This means that I could substitute the 61/25 gearset and have 4.03 to 0.72.

The T56 and TR6060 are designed to have close ratio sporting gearsets rather than wide ratio gearsets. The one I have is out of a '10 Camaro and has 3.01 first with 0.57 sixth. That's actually the same spread as the 2.66/0.50 LS1 units (so close I suspect it's just an input/counter gear change). I'll just use 3.64 gears instead of the 4.11's I was thinking of.

[Atilla the Fun]

According to the list of part numbers I've found for the Jeep T5's, they had the 4.03 first with 0.76 second using the 53/23 gearset. This means that I could substitute the 61/25 gearset and have 4.03 to 0.72.

But you have to multiply the OD ratio by the input ratio to get the ratio of flywheel to driveshaft in OD. I have the tooth counts for the input ratio for the V8 GM T5, but not for any other set of ratios for the T5.
If you have the tooth counts for the input ratio with the 4.03:1 first, please LMK.
The ratio change for the 6060 was to help offset the excessively-tall tires. The gen-4 used 25.7" tires, which is excellent. The gen-5 uses 28.7" tires, which is unforgiveable. The gen-4 used a 3.416666667:1 axle, while the gen-5 has a 3.4545454:1 that partially helps offset the too-tall tires. But the trans ratios had to make up the difference. However, with deeper ratios comes less strength. Better to keep the gen-4 / Viper ratios, and use a 3.70:1 rear gear to make up for the tires.

[The Dark Side of Will]

The BMW's use fairly short tires anyway. The price was right for this one, so significant cash outlay to change it will probably not happen until well after the car's been on the road.

The Jeeps use:
Input: 21:37
1st: 14:32
2nd: 23:31
3rd: 32:27
5th: 53:23

[Atilla the Fun]

Thank you.

[Shaun41178(2)]

This is sitting outside the GRM(grass roots motorsports) headquarters here in town. I figured no other appropriate place to post this pic then here.

IMG-20120118-00412 (Medium).jpg (64.11 KiB) Viewed 8107 times

[The Dark Side of Will]

Lol... don't see too many of them anymore.

However, that's a Concord (I think) wagon, not an Eagle. The Eagles all have urethane flares on the fenders and have 3-4" higher ride height.

[The Dark Side of Will]

My extra transmission has:

Input: 21:37
1st: 14:32
2nd: 23:31
3rd: 34:29
5th: 53:23

It has the 4.03 First and 0.76 fifth (53:23). That means I can swap in the 61/25 fifth pair and have 0.72. Sweeeet.
So it has a *slightly* shorter 3rd than the Jeep units. The countershaft with 37/34/23/X/14 doesn't show up on my parts lists, however.

I'm @$$uming it has the 9.312 input shaft since it's an AMC/Jeep, but that's pretty difficult to tell from the 9.250 input shaft with the trans assembled. Is there an external feature I can measure to definitively tell me which one I have?

[Atilla the Fun]

If the codes tag is still there you might have some luck from that direction.
I'm not convinced that ALL the 4.03 / 0.76 versions were "World Class", I'd need a pic of the front end, sans bellhousing, to determine. I sure wouldn't use a non-WC or any non-WC parts. NWCs are only good for mock-up while prepping a WC for use.

[The Dark Side of Will]

I don't think AMC's were ever built with world class transmissions. I've seen the pics showing the plug on the front of the countershaft bore to differentiate WC from NWC. I'd always assumed this box was NWC and never checked.

There's nothing wrong with an NWC transmission when used with in its capabilities. It's rated at 240 ftlbs and used with an engine that produces 230 ftlbs. I'm actually intending to swap to an engine that only makes 220 ftlbs, so the transmission should actually be even safer!

[Atilla the Fun]

I don't think AMC's were ever built with world class transmissions. I've seen the pics showing the plug on the front of the countershaft bore to differentiate WC from NWC. I'd always assumed this box was NWC and never checked.

There's nothing wrong with an NWC transmission when used with in its capabilities. It's rated at 240 ftlbs and used with an engine that produces 230 ftlbs. I'm actually intending to swap to an engine that only makes 220 ftlbs, so the transmission should actually be even safer!

The 4.03 NWC wasn't rated that high. The WC 3.75 version is only rated 230.
If you baby it, it'll live. Also remember that if you're not at sea level, then you're not making the rated torque anyway.

[The Dark Side of Will]

I won't be sidestepping the clutch... That's a recipe for a fragged T-5 in almost any application. That's why I'm building Bad Idea anyway... Transmission rated for 650 ftlbs in a 4500# car used with 400 ftlbs in a 3000# car... should be able to drop the clutch from the limiter at every stoplight and not break it.

[The Dark Side of Will]

Got the transfer case parts put together over the weekend. I haven't done the final assembly, but I have all the parts for the 2 speed case on the bench.

The Eagles were built with NP 119 T-cases. These are single speed units that are selectable for 2WD or AWD.
The Wagoneers were built with NP 229 T-cases. These are two speed units that are selectable for 2WH, AWH, N or 4WL. In low range the center diff is locked and the VC is out of the picture.

The 119 and 229 share the same castings for the external case. The volume occupied by the low range gearset in the 229 is simply empty in the 119. The 119 cases were *typically* not machined with the receiver holes for the low range shift rail, although the boss for that receiver was still in the casting. All rear cases have the bosses cast in and cored for two different clockings of the extension housing (where the speedometer cable gear drive lives). One set of holes is drilled in the 119 and the other set in the 229. The 229 drilling places the extension housing at an angle such that the speedometer cable hits the floorpan of the Eagle body. Thus the 229 is not a direct swap into an Eagle.

There are two options to swap a 229 into an Eagle:
1) Bore the receiver hole for the low range shift rail in the 119 rear case half and put it together with the 229 front case half.
2) Drill and tap the extra bolt pattern for the extension housing in the back of the 229 case half so that the extension housing can be clocked correctly for the Eagle body.

Since 1 involves indicating and boring one hole while 2 involves indicating and boring six holes, 1 is the typical option. My dad had converted two Eagles previously to 229 T-cases and has bored the receiver hole in both setups. Once you know the location to bore, it's fairly easy... indicate in on the dowel pin locations, then go to the hole coordinates and cut metal.

There is the theoretical alternative of simply drilling and tapping the cored locations for the extension housing bolt pattern using a drill press--essentially relying on the core hole to be a pilot hole. We're not sure the core holes are located accurately enough to do that. The extension housing is located by a shoulder and doesn't depend on these holes to locate it, but you still have to be able to install the bolts.

So anyway, I took a 119 and a 229 apart over the weekend, expecting that the receiver hole could be bored this coming week and I could do final assembly next weekend. I was pleasantly surprised to find that the 119 I took apart *already* had the receiver hole bored. Score! I swapped the 119 rear case onto the 229 (and vice versa) and will clean + final assemble next weekend.

There's an external bracket that has to be modified to work in the Eagle body, and my dad's taking care of that with the welder this week.

I need to get the 61 tooth gear ordered for the T5 so I can swap that over next weekend. Then with just a clean-up I'll be able to put the trans and T-case together. I can probably make time to sand blast and paint the front diff next weekend also... We'll see.

[The Dark Side of Will]

Going from 0.76 with 2.73 to 0.72 with 3.54 will unfortunately result in a 23% increase in cruising RPM, but that's better than the 30% it would have been with just the 2.73 to 3.54 swap.

2.07 = 0.76 * 2.73
2.55 = 0.72 * 3.54