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-   -   700R4 hunting for gear over 50 mph (https://67-72chevytrucks.com/vboard/showthread.php?t=588083)

BB72CHEVKT 07-10-2013 11:33 AM

700R4 hunting for gear over 50 mph
 
I have had this problem since I had the transmission rebuilt 6k miles ago but thought it was because I was running 2.8? rear end gears. I took the burb to a different shop and they confirmed I had 3.73 rear gears. I was thinking that once the gears were swapped to 3.73 the gearing would be right and solve the problem but apparently I had 3.73's the whole time. It does have a lock up kit installed. I am going to try to take it to the tranny shop next week but was wonding what you guys think.

Longhorn 70 07-10-2013 11:42 AM

Re: 700R4 hunting for gear over 50 mph
 
I would disconnect the lockup first. If that stops the "hunting" you may have adjustments you can make. It should just be one or two wires on the left side of the transmission.

Ol Blue K20 07-10-2013 12:03 PM

Re: 700R4 hunting for gear over 50 mph
 
I hope it's not bad, have you called the tranny shop to see if they think it's an adjustment issue?

BB72CHEVKT 07-10-2013 12:19 PM

Re: 700R4 hunting for gear over 50 mph
 
Quote:

Originally Posted by Ol Blue K20 (Post 6166050)
I hope it's not bad, have you called the tranny shop to see if they think it's an adjustment issue?

I am going to take in in next week. The fluid is still pink as can be.

ZombieWeinerDog 07-10-2013 07:28 PM

Re: 700R4 hunting for gear over 50 mph
 
what do you mean hunting for gears? my lockup senses vacuum and will sometimes switch in and out of lockup as engine rps decrease, then increase again.

YOUNG GUN C10 07-10-2013 07:47 PM

Re: 700R4 hunting for gear over 50 mph
 
idk about your transmission troubles but if it was hunting for another gear with the 2.8 rear gears.... switching to a 3.73 would be worse..... the numerically lower gears (2.8) are for a higher top speed, slower acceration............... while numerically higher gears (3.73) are for lower top speed, fast acceleration vehicles

YOUNG GUN C10 07-10-2013 07:49 PM

Re: 700R4 hunting for gear over 50 mph
 
do you mean hunting for gears as in trying to shift up or down shifting????

ezstriper 07-11-2013 08:00 AM

Re: 700R4 hunting for gear over 50 mph
 
what lockup system are you using ? TV cable setup ?

Ol Blue K20 07-11-2013 10:55 AM

Re: 700R4 hunting for gear over 50 mph
 
By hunting he means the trans can't make up it's mind 3rd 4th 3rd 4th etc......

Longhorn 70 07-11-2013 11:02 AM

Re: 700R4 hunting for gear over 50 mph
 
Is it hunting 3/4 or is it hunting lock/unlock?

Ol Blue K20 07-11-2013 11:19 AM

Re: 700R4 hunting for gear over 50 mph
 
Quote:

Originally Posted by Longhorn 70 (Post 6167701)
Is it hunting 3/4 or is it hunting lock/unlock?

HMMMMM.......that's a good question Longhorn. I didn't think of that, I guess that's why there's tranny guys..:lol:

Longhorn 70 07-11-2013 11:34 AM

Re: 700R4 hunting for gear over 50 mph
 
Yeah...Good transmission guys are a big asset.

If he disconnects the lockup wire on the transmission, he'll soon find out if it is 3/4 search or lock search for free.

BB72CHEVKT 07-11-2013 02:08 PM

Re: 700R4 hunting for gear over 50 mph
 
I am running a Lokar kickdown and using Painless wiring for the lockup. It can decide if it wants to be in 3rd or 4th at times when over 50 mph. I am going to take it back to the shop.

ezstriper 07-11-2013 03:31 PM

Re: 700R4 hunting for gear over 50 mph
 
thats either TV cable adjustment or issue inside trans...now you can have cable adjusted right at closed throttle and the ratio be off and cause issues...it is critical...

BustedCrank 07-12-2013 02:29 AM

Re: 700R4 hunting for gear over 50 mph
 
More then likely its locking and unlocking. It was one of the main complaints for most people with these transmissions. The problem? Most people cant keep their foot steady when they drive, they drive on and off the pedal, constantly moving their foot. Not saying that is your issue, but a lot of people have that problem.

To check if its locking/unlocking or actually shifting is easy. When driving and you think it has unlocked(or downshifted) drop the shifter down to third gear. If it shift down, it was just unlocked. If it does nothing, it is shifting gears.

Probably just a tv cable adjustment is all that is needed. If you are using a factory style cable with the adjustment up by the carb. There is a "D" shaped looking button. Push it in and slide the cable so it is all the way tight, then move the throttle to wot and it should ratchet to where it needs to be. This isnt always perfect, but it usually makes a good starting point.

Longhorn 70 08-08-2013 12:12 PM

Re: 700R4 hunting for gear over 50 mph
 
Well??? Did the shop get that bad boy going?

BB72CHEVKT 09-19-2013 12:12 PM

Re: 700R4 hunting for gear over 50 mph
 
Ok, finally got it into the shop. He fixed a small leak and the lock up. He said it was not drawing enough vacuum at idle and was turning itself off electically if I unerstood him correctly. He also fixed a leak.

67ChevyRedneck 09-19-2013 12:54 PM

Re: 700R4 hunting for gear over 50 mph
 
So have you driven it yet?

BB72CHEVKT 09-19-2013 12:55 PM

Re: 700R4 hunting for gear over 50 mph
 
Quote:

Originally Posted by 67ChevyRedneck (Post 6276689)
So have you driven it yet?

I have not picked it up yet. I will let you know once I have driven it.


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