Transmission issues.... Help

[Jakazz75]

Ok I'm having some issues... I recently had my transmission completely rebuilt from rpm transmissions got it back but kept my old torque converter( I have no idea what converter is in the truck it came with it when I bought it but I know it's an aftermarket) the truck shifts gear just fine 1st gear and even 2 seem to do just fine but in drive 3rd gear the truck only goes to 90mph ish then needs to go to od and when Im doing a pull the 3rd to 4th shifts and the rpm might drop like 200 rpm and it stays so high and just bounces of 5400-5600 rpm and the truck is actually still trying to pull but can't... Od runs out of gear at a tad over 120ish because of this. As soon as I let off the gas a little but the rpms shoot down to 3200-3400.. Where they most likely should be in the first place..at that mph..

Could this be my converter??
It's so strange because my transmission is shifting nicely.. It only too of 3rd and 4th where I have problems. It's like the converter is grabbing and letting go... Has anyone else experienced anything like this?

 

[0966Sy]

What happened to the transmission that required a rebuild? Why did you choose to reuse the TC? Did you have it flushed?

 

[Jakazz75]

Re: Transmission issues.... Help

What happened to the transmission that required a rebuild? Why did you choose to reuse the TC? Did you have it flushed?

Second day I had the truck the transmission locked up and wouldn't shift out if second... I sent it all to rpm they said everything in the Tc looked fine. .. I'm just going to take the truck to a friend at gM he knows the tranny guy up there.. See what he thinks it is. When it comes to transmissions I'm way out if my comfort zone and have no idea what's going on here..

 

[Jakazz75]

Re: Transmission issues.... Help

What mph do our trucks shift into od at in stock gearing ?
My truck is shifting 1st goes to around 30, 2nd at around 60, and 3rd around 90ish.. So I'm thinking it might be the converter. :-/

 

[powercat6]

Re: Transmission issues.... Help

What mph do our trucks shift into od at in stock gearing ?
/QUOTE]

~96 to 98 MPH at WOT at ~4500 RPM.

 

[dgoodhue]

Re: Transmission issues.... Help

Did you have a shift kit installed in the transmission? Is it an original SyTy valve body in the transmission?

 

[Jakazz75]

Re: Transmission issues.... Help

Did you have a shift kit installed in the transmission? Is it an original SyTy valve body in the transmission?

I don't think there's a shift kit.. And yes it should be the syty valve body as RPM did the transmission and I made them aware it was for a syclone.. Maybe I need to call them.. My truck is shift around 90-93mph at 5400 rpm some something is causing the rpm to go higher... I noticed in od because when I let off after it hits rev limiter at 120mph and the rpms drop down to 3300 ish right away.... So something is letting it rev up without grabbing the clutch?

 

[Osmosis]

Re: Transmission issues.... Help

A few things to think about.

First, your converter & previous transmission. Did your old transmission fail with the current converter? IF so, you have crap (metal and contaminates) inside the convert and it's now in your new transmission Did you flush the transmission lines? I use Kooler Kleen for about 14 bucks, cheap insurance.

Second, what is the line pressure of the transmission? In park, neutral, drive and overdrive, psi should be between 75-85. R = 110ish, D1 and D2 should be between 180-210. Pull on the detent cable and line psi should rise to 210. Line pressure will tell you a lot.

Third, did you properly adjust the detent cable? This can cause improper shifting if the cable is too tight or not tight enough.

Keep us posted on your findings

:tup:

 

[Jakazz75]

Re: Transmission issues.... Help

A few things to think about.

First, your converter & previous transmission. Did your old transmission fail with the current converter? IF so, you have crap (metal and contaminates) inside the convert and it's now in your new transmission Did you flush the transmission lines? I use Kooler Kleen for about 14 bucks, cheap insurance.

Second, what is the line pressure of the transmission? In park, neutral, drive and overdrive, psi should be between 75-85. R = 110ish, D1 and D2 should be between 180-210. Pull on the detent cable and line psi should rise to 210. Line pressure will tell you a lot.

Third, did you properly adjust the detent cable? This can cause improper shifting if the cable is too tight or not tight enough.

Keep us posted on your findings


:tup:

Awesome I will take that info to the transmission guy tomorrow.. Rpm had the converter , there wasn't anything to really clean up as I think he said I just got it too hot before and it melted the bands.. But they cleaned everything and put it all back together and rpm even said they dyno tested it.. :-/ I hope it's something simple like that cable.. Fingers crossed

 

[dgoodhue]

Re: Transmission issues.... Help

Unless someone changed the rear end gear your shift point vs mph aren't right. My truck shifts at ~5200 rpm and I have stock gears/tire size. My truck does the 1-2 shift ~30mph (i am not 100% on the mph because it happens so fast to log properly/plus sometimes I am spinning the tires.) 2-3 at 62mph and in 3rd gear I am not quite at 5200rpm at 111mph (trap speed of my truck).

 

[atkonkler]

Re: Transmission issues.... Help

A few things to think about.

First, your converter & previous transmission. Did your old transmission fail with the current converter? IF so, you have crap (metal and contaminates) inside the convert and it's now in your new transmission Did you flush the transmission lines? I use Kooler Kleen for about 14 bucks, cheap insurance.

Second, what is the line pressure of the transmission? In park, neutral, drive and overdrive, psi should be between 75-85. R = 110ish, D1 and D2 should be between 180-210. Pull on the detent cable and line psi should rise to 210. Line pressure will tell you a lot.

Third, did you properly adjust the detent cable? This can cause improper shifting if the cable is too tight or not tight enough.

Keep us posted on your findings

:tup:

I second this....I've worked in a transmission shop and every car or truck got a new converter and we flushed out the system with lube guards Trans cooler in the green bottle ....then flushed it again just to ensure that all the sediment had been evacuated from then system....most of the time if the transmission failed it was because of the builder....imo...keep us informed. ..

 

[Jakazz75]

Re: Transmission issues.... Help

Looks like the converter is bad... It's not too big of a deal.. Thanks guys


Also at the end of may I'm going to be pulling my entire engine / turbo / accel gen 7dfi engine management system, inter cooler, built Rpm transmission, and even selling my spare built billet crank engine... I'm selling it all!!! And doing a big swap.. I'll probably sell everything together for $7500. Details to come in may.. But I will make someone a hell of a deal.. I need the money to help find my new project ..