Hey all, I am completely new to these trucks and really these activities in general. I just bought an 84 D250 "Sno-Commander" and it has some leak coming from the trans (auto). leak is in front of the trans but not sure on specifics. I think I need either the input shaft seal or a Torque converter seal but not sure. I have to drop the trans to replace this seal and was just wondering how tall of a task that really is. Any advice or links to videos or manuals with walkthroughs would be greatly appreciated! also, any website you know of to buy parts specific to this truck would help as well. Thanks in advance

 

Correction- W250. keep getting them mixed up lol

 

You have a 4WD so you have to move the trans and transfer case back then separate the trans from the t case. Or you move back and drop the both of them. Either that or pull out the motor.

 

You'll either need an engine hoist or a transmission jack.A lot depends on of the truck is a daily driver or just an occasional chore truck. Most likely your transmission seal is leaking. If your engine has a lot of miles, I'd pull it and leave the transmission/transfer case in place and just supported on the front. I had an '84 W150 and I removed the radiator support and pulled the engine out the front. This way you can leave the hood on and the hoist won't have to go as high. Either way, you'll need to remove the bottom cover from the converter and remove the flywheel to torque converter bolts. This only bolts together one way. Shoot a spot of spray paint on the flywheel and converter while they are together. The bolt holes are NOT symmetrical. This is so it only bolts one way for balance..

If the engine has low miles and the truck is really nice, you'll remove the driveshaft, shifter linkage, t-case selector lever and raise the transmission jack under the unit. Once you have it supported, you remove the cross member. Find a way to support the engine so it doesn't bust the engine mounts and separate the bolts holding the transmission to the engine. The ones at top can be fun. Pry the converter away from the flywheel a bit and lower the assembly.

With it out, you just slide the converter out of the front and set it aside with a rag in the opening to keep just out of it. Use a seal remover to pop the old seal out. Lube the new seal and tap it in with a light hammer or seal installer. Wipe a little transmission fluid on the outer part of the input tube on the converter. This plus the fluid on the seal will keep it from damaging it and having to replace it again.Gently slide the converter back in until it stops. Now, this next part is VERY IMPORTANT! Rotate the converter clockwise until it clicks inward. You want to do this THREE times. This will seat the converter. If you force it and make it go in with the bolts, you will destroy the front pump. Instant rebuild time.When you raise the transmission/t-case assembly back into the bottom of the truck, when you mate them with the engine, there should be a gap between the flywheel and converter. If not, remove and repeat the turning and pressing in. If there is a gap, bolt the transmission to the engine block. Now you line up the paint marks and move the converter gently out to bolt them together. Start all the bolts but don't tighten them yet. ull the converter flush to the flywheel and everything should fit together. Remove each bolt and put some blue thread locker on it. Snug them down when you replace them and after they have thread lock and are snug, torque them down to specs.

If the truck is an older beater with a lot of miles on the engine, remove the engine from the front. Support the front of the transmission but leave the drive shaft, shifters and such as they are. I have trouble working on my back and this is what I do. When you remove the engine, you can then clean the engine bay up and do some maintenance on the engine.First though, remove your converter from the transmission from inside the engine bay. Replace the seal and put the converter back like previously mentioned. Make sure it is all the way in.

Now, with the engine out, replace any aged rubber hoses that are hard to get to. I generally will replace the engine mounts. I'm assuming you have over 100K on the engine. Now would be a good time to replace the timing chain. It's a lot easier on an engine stand. I'd also pop the expansion plugs out, especially on the rear of the engine and heads, and replace them. I'll bet a screwdriver will poke right through one at least. You can rinse the block out and get all sorts of sand and rust out of it. The sand is from when it was made and rust just happens over time when the anti-freeze gets weak. While you're at it, pull the oil pan and replace the oil pump with a high VOLUME unit, not high pressure. High pressure will wash the bearings but volume will compensate for worn bearings and extend the service life substantially. You can even paint the block if you want. Anything difficult to work on you can do with the engine out.

So, if it's a nice truck, pull the transmission. An old beater with a lot of miles, pull the engine. It's up to you.

 

Thanks for the detailed response, this will definitely come in handy. I wouldnt call it a beater but shes not exactly brand new either. been sitting for a few years. plan is to restore it and just used it on weekends to haul a camper/kayaks etc. unfortunately dont have an engine hoist, Id love to do all that intricate cleaning and ****. anyways, bottom is pretty rusted as far as hardware goes. ive snapped one bold with an impact already and washers are coming off in pieces lol. Is it a good idea/worth it to go ahead and replace all that? or will the originals hold for a while longer?

 

Where was the bolt you broke? Bell housing?