TH 350 question

hey all, i gotta TH 350 question for ya. my cousin has a 77 K10 Bonanza, which was originally euipped with a 350 v8 and a TH350 auto. his tranny gos into all forward gears just fine, but when he shifts into reverse it takes it a while to engage. he says it feels like its tryin to go in gear, but it jus takes it some time to shift. any suggestions? thanks in advance

Well, is the tranny fluid level fine?

yea he keeps up with that, when he first starte drivin it again (his dad parked it in the 80's) he had a major leak around the modulator. he finally got it fixed, so im sure the fluid is good.

Could be a dirty filter or a band needing adjusted, or something rubber rotted away while it sat.

thanks, il pass it along. one big problem here is that neither of us know much about autos, and were scared to go experimenting on one that works pretty good as is lol. i do have a toasted 350 here at home we could dig into, but idk how much that wold help. would you happen to know what transfer case came in a 78 k5 blazer with a 350 auto?

I beleive it was the NP205

thanks merlin, but i beleive its a full time unit, not entirely positive tho. any idea of what it would be worth, bolted to a dead th 350 on a crossmember?

Did this vehicle sit for a long time or something??? Here is my guess what is wrong. There is a Low/reverse clutch drum at the very back of the transcase. It has 3 seals on that pistons, and this piston sits in the case itself, not in a drum like the other pistons do. If the vehicle has sat for any length of time, that drum may have gotten stuck in the back of the case and is not moving all the way forward to compress the clutch pack. Don't be afraid to drive it IF all the forward gears are working OK. The use of the trans, circulating the trans fluid and getting the fluid hot may soften those 3 seals and release them and then reverse may work again. Also if it has sat for some time, try a good trans conditioner. I never recommend that stuff because it usually does not work, but what it will work for, is a vehicle that has sat for a long length of time and the seals got hardened or stuck. What that stuff can do is actually soften the seals, and also makes them swell a bit, so they can have a chance to function again. Its worth a try IF it sat for a long time. Do follow the directions though. Some of those additives say to try one bottle, then try up another if it does not work. If you get one that says that, then just get the 2 right up front and then its do or die. And do not expect it to work in the 15 minutes. It could take a couple hour drive to work. Also be sure once the stuff is in the trans, run all the gears manually too. You remember when you were a kid and driving an auto was cool and manually shifting the gears instead of leaving it in D. Well do that a few times too. It circulates the fluid through differant routes. Be cautious of Manual selected 1st. It many not want to work either, or slip, and do not let it slip. If it does, just use D to take off. That low/reverse clutch drum I am reffering to is for manual low and reverse. Low in D uses a differant set of clutch drums than manually selected Low. Hope that helps. Good Luck with it.

it has been sittin since the early 80's and was vevived around 2007. ill pass the info along to my cousin, thanks guys

Oh yeah, by all means, give that stuff above a try then. Its just sat to long and the seals have hardened up, and that drum is stuck. I say if he has not let it slip a whole lot and just trashed it, with TLC, driving it, some trans conditioner, he has a good chance at re-viving reverse. If not, just pull it and put a seal kit in it, and clutches are not that much more while at it. The bushings, thrust washers and such are still good, no need to buy new steels either. If he can't get it to work, just get whats called a banner kit will work. Clutches and seals pretty much to freshen it up. I'd say he could even get by with useing the same converter since its not likely to have shavings ran though it.

So any way to get an update as to what happened on this trans? Try any additives, rebuild it completely? WASSUP WIT IT???

That's what I was thinking!!! And bigcountry to answer the Tcase question the NP205 did come in those year of pickups however they where a twin stick tcase that may or may not have be turned into a single stick... 2 questions will answer that question...One does it have 2hi 2lo 4hi 4lo? Also is it a cast iron tcase that looks to wieght about 400lbs? if both those questions are yes then yo're looking at a NP205 which is a nearly indistructable Tcase and will likely never break!





P.S. Just read the full ime 4wd post... lol It's a NP203!

oh sorry guys i been busy lately wit work and stuff, so i havent had time to talk to him yet. and fasel, thanks for the t-case info, i dont have the knob to the thing and it wasnt in any of my vehicles. it does weigh a ton tho, it took me and my to cousins, and were all pretty healthy, to load the thing in my truck bed. and we atruggled alll the way up lol. is there any other way to tell? a model number or plate or sumthin? ill try to talk to my cousin this week about his tranny.

The NP-205 is smaller and shorter than the NP-203. It is easy to distinguish by its small round 3 bolt cover over the intermediate shaft. (green arrow)






This is an NP203 notice how there is only a drain plug and no cover over the intermediate shaft... This will tell you easily what Tcase you have if it's not in a truck and has no shifting levers.

thanks, that helps. now i know my 78 has a 205 at least, ill have to check on the other. it would be nice to have a spare 205 layin around.

Yeah or if your 78 has a 205 and you have a spare 203 laying around then get an adapter from advance adapters and put the 203 gear box in front of the 205 and have a 203/205 doubler and you'll have a 4 spd tcase with a nasty nasty lo range!!!

that would be awesome! BUT as it stands i don even have time to fill the tranny back up with gear oil lol the trucks been in the garage for over a week now, i finally got a round to draining all the water outta the tranny, t case and front diff. but i don have time to fill them back up, my stupid dead end job is gettin in my way. and to top it off, she don even wanna run right. it wont idle, and wen u give it some gas it jus skips pops and sputters. and when u put it in gear and let out on the clutch, it just wants to die completely. i wish id never backed in that stupid river. its just tickn me off right now.

ok, update on MY predicament anyway, finally got almost all fluids changed, still gotta do the rear axle then ill be done. and afer fiddlin with the choke, its runnin much better. just in time for the mud bog this weekend lol. still havent talked to my cousin abt his problem tho. bear with me yall

Oh we be here waiting for updates!! And as far as your problem goes I was going to suggest the carb or the timing being the cause of your problem but as you stated the choke was the prime suspect I'll still bet that your timing is a cause for concern... Also check your plugs and wires as well you may have fouled a plug if you got water in the motor.

well thats the debate, the motor never really got wet. the truck was nose up i the river and i never shut it off so i know water didnt go up the exhaust. i found a couple of cracked vaccum line hose covers, im gonna get some of those today. to clarify, the truck runs good now, but it doesnt have a consistent idle. it will idle a bit high for abt 15 secs, then drop a couple hundred rpm for about 15 secs, then go back up for abt 15 secs. and this is continuous. this is just sittin idling with the trans in neutral. i havent actually tried to move it yet.

Ok if the ruck was nose up was the tank under water? Those mechanical fuel pumps create quite a decent amount of vacuum in the tank it could've gotten water in the gas tank through the tank vent and the sending unit lid if the rubber o ring is old and has lost it's seal... some fresh gas may cure your idle issue...

Just my $.02

When you changed the fluids did you notice any water in anything? The reason I ask is if the front diff got water in it then it was most likely deep enough to get near the engine. Then all you would need is the fan to fling it around and voila' electrical (ignition) problem. I would check the distributor cap.

lol! But really that is also a highly probable cause!!

thanks guys i was alredy figuring that it needed fresh gas, and if that doesnt cure the problem ill look into the ignition system. i started it to move it while ago and its back to the same old problem. i shut it off and turned off the lights, i just dont feel like workin on it tonite

OOOHHHH !!! haha and i have an update on my cousins trans, he has taken it out and he thinks its the valve body. said hes tried all kinds of sdditives, and he belives its the valvebody so hes gunna change it out. ill try to keep yall updated better