I was of the understanding that the older tcases didn't have synchros, so you couldn't shift on the fly - had to stop. Maybe that is incorrect - either way, it's no big deal.

 

I understand now. You still have ADD. My bad.

i have no syncros. With my hubs locked, i can shift into 4wd at 60 mph. I just let off the gas to make sure both front and rear are spinning together, and it slides in without any effort.

The syncros were for ADD trucks, becasue in order to shift into 4wd, you'd need to spin up the front driveline. With manual hubs, and no ADD, with the hubs locked, everything is spinning, so nothing to get up to speed.

My mistake. Apologies

 

Ohhh - right, that's exactly it. Thanks for the explanation.

 

I did a dual setup in my truck 88' forward shift front topshift rear. I was told by alot of people to steer clear of the old t-cases pre 86. Thaey are not as strong as the newer ones and are noisy.

 

Well, after doing yet MORE research, I see that the core charge credit is CONSIDERABLY higher than what I pay for transfer cases ... I may snatch up every one I can find and send it to Marlin... need to check the price for shipping and if/how I could do it from work (on pallets).

 

I just got done slapping a dual setup behind my 3.0. Definitely the best mod I have made so far. The control and torque is unbelievable.

Crossmember: I'd think you'd be looking for a new one. The mounting point of the transfer moves back the distance of the entire front transfer and adapters. At the very least, you'd have to move the stock crossmember and modify it a bit for DS clearance. Might also want to consider getting a new mount if yours is old and warn. The new torque will really do a number on it.

I ended up with the FROR setup. That's a really, really nice way to go. I got my dual setup used and it came with it... but I am very glad it did. The FROR ties the front transfer and rear transfer together. With the stock crossmember, you'd only be supporting the entire assembly with one factory mount... back to the new increased torque issue.

Driveshafts: Those will of course very, but here are the dimensions from my swap.

FR: 26 1/2" stock (square DS, SAS) +6 1/4" after crawler (now 32 3/4")
RR: 50 1/4" stock (rear leaf swap) - 7 1/4" after crawler (now 43")

I'd suggest getting the harder shift gate springs from either Marlin or TG. I think it helps keep your sticks from popping out of position. I have heard the springs are much easier to install with the cases out of the truck.

The speedo extension cable from Marlin is very nice. Without it, my speedo would not have reached. My vehicle is mechanical, so this may not apply.

I cannot shift from 4L to 4H on the fly. I haven't tried shifting from 2H to 4H. I do not know the exact year of my cases.

 

Did you do a clocked adapter, or straight? What did you do for the shifters?

 

Really?? You shift from h2 to h4 at 60mph?? You have an '87 right? I have always slowed to 5mph or less to shift from 2wd to 4wd on my '87. I guess I was always just being careful.

 

We've owned the truck since 89, and been doing it that way since we got it.

The 5mph or below is for low 4. The old trucks came with a sticker on the glovebox that had those instructions for shifting between 2 and 4.

The way a non add equipped truck works is when the hubs are in, the front driveline is spinning the front output shaft exactly the same speed as the rear output shaft (assuming you have the same sized tires front to rear, and the same gear ratios in the diffs, but i figure most do).

When shifting, you do want to let off the gas, so that everything is coasting, to take stress off of gears, then just gently pull back.

If you feel more comfortable with slowing, then by all means. I guarantee if you stop, you have almost zero risk of any damage (like if you try to go to 4wd at speed, but forgot to lock your hubs). But stopping isn't nessesary.

 

Straight adapter.

Shifters... they came out pretty slick, if I do say so myself.

Ended up with the front stick being basically in the stock position, next to the 5spd stick. The rear stick I snuck into the factory cup holder.

I can try and get a pic if that would help. I think it looks pretty clean. My bet is most people wouldn't even notice, except to try and figure out why 3 sticks from the factory.

I cut both sticks and welded in a dogleg to get the angle and position I needed. I still need to tweak them a bit to be perfect... but they work well.

I think the short throw kit from Marlin or 4Crawler for the rear case would be really helpful for fitting the stick in very tight places... but I didn't want to spend the money.