2F into a 72 FJ40 need transmission advice (2 Viewers)

[96 Bronco]

So I have spend an inordinate amount of time moving the gears by hand and trying to understand how this works. First couple pic is what I believe to be neutral. The 3rd pic is the gearbox in 3rd gear. I can not get it to engage 4rth. Can anyone tell anything from this picture? I can physically move (wiggle a bit) the brass synchronizer on the back side of the front shift collar that allows it to engage 3rd - but the one on the front which would allow it to enter 4rth is too tight to move. I poured some gear oil over this area and tried to work it in. I’m letting it soak now.

I’m confident that I understand the shift cover positions and that I’m engaging both collars and the reverse fork when I install the top cover. I hunker down and tip the cover on its side a bit so I can see the forks engage the collars, then straighten it out, then down. When you install the shifter and hit reverse you can hear an audible clink of the reverse gear sliding over and engaging.

 

[96 Bronco]

Update. I picked up another 4 spd transmission with its transfer case still attached as well as some bucket seats. The transmission splines turned easily enough on the ground, the gears shifted easily, all seemed good. With this spare laying on the garage floor I was ready to do whatever it took to this stuck transmission I already had in the FJ with the safety net behind me. I was able to free the stuck 4rth gear collar - although it took a good bit of force. I then re-assembled the top plate and fired it up - same problem - wants to drive while in neutral. I was ready to stick my hoist through the passenger door and drop the tranny then thought again about a very early comment Mark made in regards to the output shaft shaft pressure on the bearings. I removed the nose cone and very very carefully inspected the spacer I had cut earlier when installing the 3 spd transfer case. Well, my second job (how I pay for FJ parts) is as a trim carpenter and I have a very nasty habit of always cutting things waaaay to tight. When I'm doing some framing in a basement or in my shop for example I always cut things unneccesisarly tight and it ends up taking longer than anticipated. So, I cut this spacer the exact length of the splined portion of the output shaft - the shoulder on the shaft was preventing the nut from making sufficient contact with the spacer and therefore I was not getting the pressure forward I needed. I stuck a washer in there to test my theory and PROBLEM SOLVED! So I recut a spacer about an 1/8" longer and went on my way (more on this later).

Below are some pics of the twin stick install - I do not see how this would have been possible without this kit. Even this linkage is so close to my floor pan that its scary. see the finished install pic, modifications to my floor would have impacted the gas tank and seat mounts making this an even more complicated undertaking.

Once I had everything buttoned up and I backed the FJ out of the barn and it felt like I was dragging an anchor. I checked the rear wheels for drag and that was not the culprit. I could not roll the vehicle by hand on the shop floor with it in neutral - but I could if I also put the transfer case in neutral - ??? I thought I had the twin sticks in the wrong orientation maybe - but the problem ended up again lying with the output shaft spacer behind the transfer case. I had it soo tight now that it was dragging. My Haynes manual list a torque spec of 90 ft/lbs so I accessed the cone from underneath, backed off the nut and reset to 90 ft/lbs. Better, but still dragged. So I went through a series of back the nut off a 1/4 turn, get up, pop the transmission in neutral, try to push it, repeat until it got to what felt like a normal amount of effort required to push this small vehicle on the shop floor. After this series I went for an initial drive and WOW - the 4 spd was well worth the effort. It makes the overall driving experience well worth it and its MUCH quieter. Even with my old 3 spd transfer case still attached the noise has been cut in half I would conservatively estimate. The gear ratios are much more pleasing and the clutch feels a lot smoother than the old.

Its not all sunshine and unicorns however. My new to me 2F motor has a few leaks and that will drive me crazy. the main oil leak is coming from the plug on the head between the #4 and 5 cylinders. This is well documented on MUD and I'm thankful because I thought for a minute my head might be cracked as the oil seepage starts halfway up the head. I'll get some pics of this repair process very soon. My valve cover also leaks, as well as I believe the upper radiator hose - easy fixes. There's a bunch of oil accumulated on the back of the oil pan, bellhousing area that is probably a rear main .

 

[Dizzy]

Could you speak more about your spacer incident. Why is the input shaft spacer not the proper length when you got it? Did you face it on a lathe? Was this a custom part to fit the 3-speed transfer case, instead of the one that would have come with the 4-speed? What did you use for the input gear stopper?

 

[96 Bronco]

I had to cut my own spacer, and I did it on my only metal cutting device - a chop saw. I tried to get the ends parallel but it was on the bench grinder. If you had a 4 spd case donor it has the correct spacer, but I couldn’t source one

Input gear stopper? There are spacers available from Advance Adapters to replace the PTO gear if that’s what you mean

This pic is the first attempt that ended up being a hare to small

 

[Dizzy]

The input gear stopper is the first thing behind the rear output bearing on the transmission; it, plus the PTO gear or PTO spacer, keep the input gear situated.

 

[96 Bronco]

Maybe I'm missing something? when I took the case off the old transmission - all that came off the transmission output shaft was an input gear and a PTO gear. Both were 10 spline. When I put that case on my new 4 spd transmission I put back in the new conversion input gear and a PTO spacer - that's all that's inside the case. then I have the rear bearing, then the spacer in the pic above, then the Toyota thick washer, then the Toyota stake nut.

 

[96 Bronco]

Anyone familiar enough with guages to answer this - my 1F motor had a temp sending unit in the side of the block on the driver side. My new 2F has is on the top of the head near the carb. I hooked up to the this location on the head and now my guage is acting crazy. I'm kind of at the limit on pouring money into this thing so want to be sure of what I really need

 

[Dizzy]

I don't understand why the input gear stopper is just on the 4-speed, but, that is consistent with the manual. How does the 3-speed gear differ from the one that you replaced it with?

 

[96 Bronco]

Difference is only the internal diameter and spline count so it will fit over the 4spd shaft

 

[MoCoNative]

Rear bearing of 3 speed projects into the transfer, nose cone of 3 speed input transfer gear rides right on it. The 4 speed has the extra case/cover on back side of transmission. This requires a spacer between rear trans bearing and input gear, then long spacer to account for PTO gear then the bearing and then another spacer on the back end.

If you don't have the short spacer your gear is floating forward, that would cause bind as the gears get out of alignment. Open the PTO cover, are all the gears aligned/flush when looking into the case.

Go and read the thread I linked, he ends up the same problem, it shows how it is supposed go.

 

[96 Bronco]

Well, I thouht I was done till now! I’ve been driving it no issues

 

[65swb45]

@MoCoNative makes a good call. If you’re not 100 percent sure the spacer is in there, you should pull the PTO cover.

 

[96 Bronco]

I'm still putting miles on the new setup and have some more questions. I'm super pleased with the driveability around town and up to 55 mph - but its still disappointing at hwy speeds. Comfortably cruises at 60, but much faster feels like its straining. For comparison, I drove a friends 74 fj40 today. he has a tired old looking 1F with headers and a tired looking Weber. He also has a 4 spd. First he drove and we were on the interstate comfortably cruising at 65 and could hit 70 pretty easy - mine can't do that at the same noise level his could. then I drove it and i was not super impressed - my 2F definitely pulls harder and feels stronger than his motor - but he can go faster - what gives? My friend seems to think its my front hubs - they are the old type always locked. i don't; think so b/c i don't have my front driveshaft installed. Can just turning the differential be enough drag to be the difference?

 

[96 Bronco]

Forgot pic

 

[Jordan85]

Possibly...I have a 2012 Ram 2500 with the 6.7 Cummins. Probably 3x the horsepower and 5x the torque of a 2F....I’ll get to the point. Dynatrac makes a hub conversion to free up extra power, increase fuel mileage, reduce wear etc. If it makes a difference in my truck, could make the difference for your 40. That or gearing or tire size...

 

[96 Bronco]

Anyone with experience in a 40? I have a Ford F-250 diesel that I routinely forget to unlock the manual hubs on - and I don’t notice. Probably because like Jordan said it has a metric s*** load of HP and torque!

 

[RustyRanger]

It's possible the front end being always engaged might slow you down a bit, though your engine with a header will be a bit noisy than a cast manifold. Might be part of it?

 

[96 Bronco]

I have a stock manifold on mine

 

[96 Bronco]

I guess a little is all we are talking about - I want another comfortable 5 mph at the top end. But as far as I can tell from Specter, after shipping it’s $600 to get a set of locking hubs. I want to make sure this will benefit me $600 worth before buying. I’m already so deep in this vehicle every penny counts now

 

[Dizzy]

I can't imagine that you have that much gear drag, if it was enough to slow down a 2F then I'd look into drivetrain issues. I'd do locking hubs more for component longevity. I'd look into the carb, spark, and distributor for further performance.