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Bryan Irons
Curing the Weakest Link
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Bryan Irons
Curing the Weakest Link - Transmission
1 - The T-19 we scored for this swap is a fully synchronized brother to the venerable T-18 4-speed transmission made famous in the off-road world. Many versions are available so it is good practice to verify what you are dealing with. Ours has the more common 4:1 first gear ratio and will match the rest of our drivetrain well.
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Bryan Irons
Curing the Weakest Link - Transmission
2 - Our Advance Adapters kit includes a mainshaft, seals, snap rings and gaskets. Also included are a new 27-spline input for the Dana 300 (which we didn’t use), and an aluminum adapter with clocking options and foot mount for a GM style transmission mount.
3 - Your goal is to remove the main shaft and input shaft from the transmission. The T-1X series of manuals are relatively easy to work on with a factory service manual found online. Throw your cell phone in a Ziploc and plan on taking LOTS of pictures. Watch out for all the small needle bearings that will likely scatter onto the floor… you will need to collect all of them for reuse.
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Bryan Irons
Curing the Weakest Link - Transmission
4 - MacGyver is still our personal hero and using his lead we managed to disassemble the entire transmission without the recommended “specialty tools.” You will require a few different sets of bearing pullers and a good set of snap ring plyers. These MAC units of ours are 30+ years old and still have no equal.
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Bryan Irons
Curing the Weakest Link - Transmission
5 - With everything out, get a clean work surface and remove all the gear clusters off the old main shaft and stacked in order for reassembly. Remember to inspect the synchros and watch for chipped teeth. Parts are available and this is the time to change them.
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Bryan Irons
Curing the Weakest Link - Transmission
6 - You can see how much shorter the AA mainshaft is. Make sure your shift dogs move smoothly into position and the unsplined gears rotate with ease.
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Bryan Irons
Curing the Weakest Link - Transmission
7 - Remember all those needle bearings you chased all over the floor? A trick we learned is to use petroleum jelly to hold them in place for reassembly. Avoid grease because it will not break down and allow the gear oil to flush everything out.
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Bryan Irons
Curing the Weakest Link - Transmission
8 - With the main and input shafts back in the main housing, it’s time to bolt on the adapter housing from AA. Overall, we gained a massive strength upgrade and only added an extra 5 cm to our drivetrain length over the anaemic T-177.
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Bryan Irons
Curing the Weakest Link - T-Case
9 - The Advance Adapters Dana 300 output shaft upgrade was next on our “To Do” list. Included are an entirely new output housing with bearings and a 32-spline main shaft. When you order your unit, make sure you know what rear yolk you have as they will include a new one. Our 1310 Double Cardan driveshaft will remain for now.
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Bryan Irons
Curing the Weakest Link - T-Case
10 - In order to reach the rear output assembly and remove it, we need to pull the Black Box-I out from in front of the entire assembly. This is fine, as we need to swap out the 23-spline input shaft for a 27-spline that North West Fab supplied us with.
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Bryan Irons
Curing the Weakest Link - T-Case
11 - Our first word of advice; use a centre punch to mark the indexing of the crawl box to the transfer case. The clocking process is quite involved so we canted to relieve ourselves of going through this headache again. Our second word; drain the fluids now before you have to explain why all your cloths stink like gear oil.
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Bryan Irons
Curing the Weakest Link - T-Case
12 - The beauty of the Black Box-I is the lack of any spud shafts to break. It couples directly to the Dana 300 mitigating any weak points.
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Bryan Irons
Curing the Weakest Link - T-Case
13 - With the Black Box stashed away, we needed to pull the yolk off the rear housing. Use an impact to spin the stover nut off, or grab a breaker bar and a pipe wrench to convince it apart.
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Bryan Irons
Curing the Weakest Link - T-Case
14 - A three-jaw puller is used to yard the old housing off of the shaft. The rear bearing is a light press fit, but still a press fit. The shaft is “trapped” inside the housing and its only escape if through the front of the housing.
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Bryan Irons
Curing the Weakest Link - T-Case
15 - With only a few minor flesh wounds and our kids with a new vocabulary, the main output shaft was pushed out the front of the case. The common failure point on these units are the speedometer splines and right where the yolk splines end. As you can see in the new AA shaft, these weak points have been eliminated and the addition of extra metal means we’re going to have to try much harder to break this 32-spline brute.
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Bryan Irons
Curing the Weakest Link - T-Case
16 - The included plastic speedo splines lock into place with supplied snap rings. All this needs to be assembled after the primary bearing is assembled on the shaft. It is a light press fit and can be easily removed in the future if need be.
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Bryan Irons
Curing the Weakest Link - T-Case
17 - It was nice to have the new rear housing and shaft already set up with shims at AA’s factory with the proper bearing preload allowing it to simply bolt on with the supplied Allen head bolts.
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Bryan Irons
Curing the Weakest Link - T-Case
18 - The final task is to install your speedometer gear and index it according to the marks on the original cable drive unit. Our Advance Adapters kit even came with a new O-ring to seal it up.
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Bryan Irons
Curing the Weakest Link - Black Box
1 - Before we bolted the T-case and Black Box-I assembly back together, we needed to pull the input shaft and swap out the 23-spline unit for the 27. North West Fab’s design of the Black Box is nothing short of exceptional and we only needed our trusty snap ring plyers and a press to swap the main bearing onto the new shaft.
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Bryan Irons
Curing the Weakest Link - Black Box
2 - Using the indexing marks made before, the parts simply slide back together and bolt in with a little anaerobic sealant around the flanges.
Story & photos by Bryan Irons
Building a gearbox to handle 'Merican Metal Menace
Our trail hero “Stinky Jeep” has been in the pages of 4WDrive for a number of years with upgrades ranging from interior set-ups to wheel testing with nary a whimper coming from it’s heart and soul. The wheezy 304 V-8 has been reliable as can be expected, but it’s really just a 10-year-old toothless Pitbull. Our original plan has worked flawlessly with just general maintenance, but the easy life is now all but a dream with the 400-plus horsepower Merican Metal Menace AMC V-8 being sunk under its metallic green façade.
Being the simple folk we are, we ran out of counting fingers performing theoretical math trying to decide if the drivetrain would live long enough to see another winter. It wasn’t looking good. Our hillbilly algorithms showed a number of flaws; the aluminum 4-speed manual transmission was going to crack in half just before it blew up the itsy-bitsy 23-spline output shaft; the BlackBox-I from North West Fab was going to laugh off the destructive force as it transmitted the shock load to the Dana 300’s miniscule 26-spline outputs and started popping the ‘parts store’ U-joints like they were tortilla chips.
We like having a manual transmission and our rig just doesn’t have room for an overdrive unit that could be deemed “reliable”, and a super deep 1st gear is overkill in a rig with dual transfer cases (four-figure crawl ratios are good for nothing but making trail clots, you know who you are), so a Borg-Warner T-19 was our target transmission. A fully synchronized unit was scored off the local Craigslist listings from a mid 80’s Ford diesel. We now had the “hard parts” and it was time to score some aftermarket goodies to put the new beef to work.
Using Advance Adapters Website as our “swapping for dummies” guide, we now had the right bellhousing, clutch and flywheel, and it would bolt to the transmission, but everything else needed adapters to work. A T-19 to Dana 300 adapter from Advance Adapters was ordered up along with a HD output shaft kit for our T-case. The main shaft of the T-19 is swapped out for a precision ground and heat-treated unit with 27-splines on the output side and a custom cast aluminum adapter plate. Dana 300 T-cases are originally 23-spline units, and 27 doesn’t go into 23… we’re talkin’ splines here; get your mind out of the gutter. Advance knows this and includes a new 27-spline Dana 300 input housing, but this does us no good, as our phenomenal BlackBox-I from North West Fab does not use a standard Dana 300 input. Luckily, the BB-I’s design lends itself to easy adaptation and we ordered up a new 27-spline input from North West Fab.
We were told that our new transmission had been recently rebuilt, but we have been fed this line in the past. We covered our butts by calling Kelowna Transmission and Auto Repair to make sure they could get their hands on a rebuild kit should our juju run out. So with all our parts in hand, it was time to head into the shop and let the stagnant reek of gear oil infiltrate our nostrils and flesh.
With a few wheeling trips under our belts and having exactly zero failures from motor mount to drive shaft, we’re calling this a complete victory. But now that we’re crackin’ axle shafts like ankles in an old folks home, we’re onto chasing weak links. In the mean time, follow along as we rip and tear into the dark underbelly of Stinky Jeep.
Advance Adapters - www.advanceadapters.com
North West Fabrication - www.northwestfab.com
Kelowna Transmission & Auto Repair – www.kelownatransmission.com
ARP – www.arp-bolts.com