Just bought a 88 Bronco II and have a few questions

[dixie281]

Howdy all, I have a few questions about my new truck. It's an 88 Bronco 2, 2.9L, auto trans, pushbutton 4WD (conversion to rotary 4x4 switch on the console is underway). I hope to eventually modify it and give it some more power (a 4.0 swap seems popular, or possibly a 302 swap) but for now I need to run what she's already got. I just started reading up on it, so please forgive and correct me if I am wrong about anything.

So...how much trouble should I expect from the 2.9L? I hear if you overheat them then the heads are likely to crack. I will be takin the truck off-road in mud and water, and I am worried that if I drive into water of any appreciable depth the sudden temperature change will hurt the supposedly weak heads.

I read that some people are finding two thermostats in their 2.9L? Which one belongs and which one doesn't? From what I gather from this forum, there ain't supposed to be a thermostat in the upper radiator hose/line, only in the bottom. Is that right? Also, I want to keep the motor nice and cool to avoid head problems. Can I go down to a 180 degree thermostat? Radiator is clean and flows air and coolant freely.

That's all I can think of right now, I am sure I will have more ?'s soon. Thanks for the help!!

Regards,
Andy

[drofman]

The 2.8L is the motor that you have to watch out for the 2 t-stats, 2.9L only goes in the top hose. Keep the 192 t-stat, it will run better. These motors don't like to get hot, you're right they will crack heads. I've got over 300,000 on mine 88 and I've never had the heads off (done a couple of radiators, water pumps and a mess of heater cores) and I will still go out in the middle of nowhere with it. The Auto tranny is the weak link and sometime the motor on the transfer case likes to get stuck on the pushbutton 4WD rides. Mine has only let me down twice, the TFI Mod and the lift pump in the tank. I did have a Voltage draw that would kill the battery in 3 days that turned out to be the lumber support. Rad. arm bushing need to be replaced every once in a while and I replaced my drag link with greaseable fittings. I love my bucker and can go anywhere a Jeep can go with the A/C on.

[dixie281]

Thank you for the help drofman (and anyone else that chimes in)...it will run better with the 192* t-stat? You mean like gas mileage wise or overall? I am just worried about thermal shock to the heads if it's running with the 192* stat and I drop the truck down into a mudhole and get the heads wet. Am I just being overly concerned?

I suspected the auto tranny was a weak link. I'll be bypassing the radiator cooler (if it even has one) and replacing the little external trans oil cooler that's on there now with a big stand-alone unit. Probably add a temp gauge on the cooler inlet too. Could you please confirm that my truck came with the A4LD transmission? I ain't ever seen one of those in person so I don't know for sure, but some searching seems to say that would be the trans I have. And is it electrically shifted like an E4OD or completely hydraulic?

When you say TFI mod, are you saying the TFI module let you down, or are you saying there is a modification we can make on these trucks that failed and let you down? I know the TFI modules go bad, if there is a mod I can do to help mine live longer I'd love to do it.

EDIT: also, I have some electric Autometer gauges somewhere that I want to put in...oil press, temp, fuel, tach and speedo. Is my speedometer mechanical or electrical? If it's electronic I can use my autometer one, it can be calibrated to work with most any factory speed sensor.

Reason being, is that my factory temp gauge don't work and I don't not having an oil pressure gauge anywhere on my instrument panel. If I am going to have it apart, I might as well make a custom panel and use my tach and fuel gauges too!

Thanks!!

Andy

[drofman]

I know it sounds wrong but any late model motor is designed to run hotter due to emissions. As for thermal shock, there is a lot of metal around the cly. That will wick heat away unless you put it into a lake. If your cooling system is working good leave the tranny cooler and install an external in-line. I did put a physical temp gauge in mine, but don’t worry about it moving all over the place. Mine will bounce from 190 to 200 with the a/c on a hot day. I put one in for a friend of mine and he drove me crazy cause he was used to a temp gauge that would stay in one place. The TFI module went out on mine but if you are worried about it I believe some of the Aeorstars had a TFI that was mounted on the fender with a heat sink built in. Now don’t sweat the small stuff and drive it and remember “If it ain’t broke, don’t fix it”

[dixie281]

Lol, I have always run aftermarket gauges in my toys and I am used to them goin all over the place. I like it, lets me know what's really going on as opposed to the factory gauges. I fixed the factory temp gauge and took the truck out to Redneck Yacht Club this past weekend, went through some fairly deep water and had no problems so I ain't worried anymore. I think I'll be building a snorkel though, just because the factory intake is right above the bumper.

All in all, fun truck! I was surprised at how much mud it would go thru just in 2wd with stock wheels and all-terrains...I think a 3" lift, some 31's and a snorkel kit will be it for this machine. I miss having a pickup with an open bed, but I'm fairly set on keeping this truck too! Goes just about anywhere a Jeep will as far as mudholes go...

Thanks for the help!!

EDIT: oh yeah, and I'll be wanting some manual hubs too. Seems like I have to reverse for a good 8 or 10 feet to unlock the stupid auto ones. Can anyone recommend good manual hubs for my truck? I will probably just lock them in when I put them on and leave it at that. Shouldn't hurt anything unless I forget and leave it in 4x4 on the highway or something