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Hi all, I have a 78 f150 automatic. When the truck is in drive, it's kind of sluggish starting off. If I start off in "1" the trans is very quick to respond. As I manually shift it, it still feels good. Would the vacuum modulator have anything to do with that? It also shifts way too quickly in drive not letting the engine get into a good rpm range. Would an adjustable vacuum module help shift points or do I have to look for a higher stall torque converter?
I, the AMAZING Tony, will use my magical
diagnosis power of the internet to tell you what is wrong with your truck.....
D on the column is 2 on the transmission. Your transmisison has a second gear start feature, that you are using. Count how many clicks you hear/feel. Stop at 3, then try 4.
Try driving your truck in N, see what happens. If it magically works, you need to adjust the linkage under the truck, so when the trans is in D, the pointer on the column reads the same.
I, the AMAZING Tony, will use my magical
diagnosis power of the internet to tell you what is wrong with your truck.....
D on the column is 2 on the transmission. Your transmisison has a second gear start feature, that you are using. Count how many clicks you hear/feel. Stop at 3, then try 4.
Try driving your truck in N, see what happens. If it magically works, you need to adjust the linkage under the truck, so when the trans is in D, the pointer on the column reads the same.
You are amazing!! Yes, it's off a little and I've been meaning to adjust it back to normal.
BUT,
if you're Truly Amazing, tell me why the previous owner swapped in an automatic and took out the 4 speed? I'm still scratching my head over that one.
Ladies and gentleman, INTRODUCING MY YOUNG APPRENTICE AEROBB!! Give him a nice round of applause ladies and gentlemen, this is his VERY FIRST on stage performance!!! Hopefully it's the first stage, the one leaving town
That would have been my guess too, or that the person hated shifting, and did not want to buy another truck.
So, you never did tell us if our magical insite has solved your problem or not?
Well, if I close one eye, the shift indicater lines up perfectly. That will get me by for now till I adjust the linkage. I'm getting tired of driving around in circles too.
I'm going to mess with the vacuum mod this weekend. Hopefully it won't be too cold or raining.
er, so that was the problem?? Or its mis-aligned, but the problem is still there when the trans is in the proper detent?
The trans would be in the proper detent but the indicator needle is off. The steering column has been replaced and the automatic trans has been swapped in as the truck used to be a 4 spd. To fix the needle position I have to adjust the linkage to the column.
Yes, the problem still exists in it's proper detent. If I'm in 1 the truck could spin the tires like the converter is locked up. If I leave it in D it goes but acts like a slipping clutch on a stick shift. Overall the trans shifts firm although I would like to widen the shift points and increase them 300-500 rpm's. I'm hoping adjusting the vacuum module will help some as I don't really want to put a new torque converter in it.
I doubt that you have a converter problem. I would try the vacuum diaphragm first. Try adjusting it and if it doesn't help then go to the local parts house and get another one and try it. They are cheap just be sure you get the one with the black ring color code. If that doesn't help then the governor could be stuck, or the valve body loose or sticking. Get yourself a good repair/service manual for the tranny. The problem could be very simple and I would try to figure it out myself before going to the tranny shop and paying through the nose for a rebuild when you might just have to tighten up a loose valve body.
We used to laugh at the old tranny shop commercial that said "Bring in you vehicle for our free evaluation, only half of the transmissions that come in to our shops need rebuilding." We always added at the end of the commercial "but they get one anyway."