Turbo 350 problem... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jmanthony65 · 10-18-2010, 02:35 PM

I picked up a 73 K5 last week. I has a 350 with a turbo 350 trans. When I loaded and unloaded it off the trailer everything was fine. However, when I went to back it into the shop it wouldn't go into reverse. It does fine when i drive but no reverse. Gonna try changing filter and fluid today but I'm not ver optimistic

Any other suggestion on what to cheack before I pull it completely?

clinebarger · 10-18-2010, 02:55 PM

Quote:

Originally Posted by jmanthony65

I picked up a 73 K5 last week. I has a 350 with a turbo 350 trans. When I loaded and unloaded it off the trailer everything was fine. However, when I went to back it into the shop it wouldn't go into reverse. It does fine when i drive but no reverse. Gonna try changing filter and fluid today but I'm not ver optimistic

Any other suggestion on what to cheack before I pull it completely?

Did you check the fluid level?

3r!c84 · 10-18-2010, 03:58 PM

think with your dipstick.........

jmanthony65 · 10-18-2010, 06:30 PM

yes i checked level.. I just got through changing fluid and filter, it brought reverse back but had to really rev it up to get it to catch. That lasted about 10 minutes... looks like rebuild time...

3r!c84 · 10-18-2010, 06:35 PM

How was the fuild before you changed it? Dark? Smell like burnt toast ?
Posted via Mobile Device

SSedan64 · 10-18-2010, 07:10 PM

If Manual Low-1 works correctly the Low/Reverse clutches should be fine. May be Modulator valve or Reverse boost valve sticking/binding.
Put a Pressure gauge on it & see what's happening 1st. Line & 1-2 ports.
Ports>> http://th350.netfirms.com/pages/7a2-02.jpg
diagnosis Pg. 5 http://th350.netfirms.com/pages/7a2-05.jpg & 6>> http://th350.netfirms.com/pages/7a2-06.jpg
Pg. #24>> http://th350.netfirms.com/pages/7a2-24.jpg and #25 >> http://th350.netfirms.com/pages/7a2-25.jpg show the fluid path and which clutches are engaged etc..

SSedan64 · 10-18-2010, 10:36 PM

I should've asked, does it have engine braking in manual Low-1?

jmanthony65 · 10-19-2010, 11:14 AM

The fluid did not look or smell bad. As far as I can tell the engine braking is normal. It has started to make a noise when shifting into reverse not really a grinding sound more like a light crackling sound.. I'm at a loss so any help will be welcomed. I dont really know much about transmissions so where would I put the pressure gauge?

10-18-2010, 02:35 PM	#1
jmanthony65 Registered User Join Date: Aug 2008 Location: Nacogdoches,TX Posts: 57	Turbo 350 problem... I picked up a 73 K5 last week. I has a 350 with a turbo 350 trans. When I loaded and unloaded it off the trailer everything was fine. However, when I went to back it into the shop it wouldn't go into reverse. It does fine when i drive but no reverse. Gonna try changing filter and fluid today but I'm not ver optimistic Any other suggestion on what to cheack before I pull it completely?

10-18-2010, 03:58 PM	#3
3r!c84 Badass Join Date: Jan 2009 Location: lox. fl Posts: 4,586	Re: Turbo 350 problem... think with your dipstick......... __________________ Think outside the box? -84c10 (1stcar)→My Build← -00 Saturn 5spd drop a gear and disappear! 1/4:13:90

10-18-2010, 06:30 PM	#4
jmanthony65 Registered User Join Date: Aug 2008 Location: Nacogdoches,TX Posts: 57	Re: Turbo 350 problem... yes i checked level.. I just got through changing fluid and filter, it brought reverse back but had to really rev it up to get it to catch. That lasted about 10 minutes... looks like rebuild time...

10-18-2010, 06:35 PM	#5
3r!c84 Badass Join Date: Jan 2009 Location: lox. fl Posts: 4,586	Re: Turbo 350 problem... How was the fuild before you changed it? Dark? Smell like burnt toast ? Posted via Mobile Device __________________ Think outside the box? -84c10 (1stcar)→My Build← -00 Saturn 5spd drop a gear and disappear! 1/4:13:90

10-18-2010, 07:10 PM	#6
SSedan64 Registered User Join Date: Oct 2008 Location: Macon, GA. Posts: 89	Re: Turbo 350 problem... If Manual Low-1 works correctly the Low/Reverse clutches should be fine. May be Modulator valve or Reverse boost valve sticking/binding. Put a Pressure gauge on it & see what's happening 1st. Line & 1-2 ports. Ports>> http://th350.netfirms.com/pages/7a2-02.jpg diagnosis Pg. 5 http://th350.netfirms.com/pages/7a2-05.jpg & 6>> http://th350.netfirms.com/pages/7a2-06.jpg Pg. #24>> http://th350.netfirms.com/pages/7a2-24.jpg and #25 >> http://th350.netfirms.com/pages/7a2-25.jpg show the fluid path and which clutches are engaged etc.. Last edited by SSedan64; 10-18-2010 at 07:12 PM.

10-18-2010, 10:36 PM	#7
SSedan64 Registered User Join Date: Oct 2008 Location: Macon, GA. Posts: 89	Re: Turbo 350 problem... I should've asked, does it have engine braking in manual Low-1?

10-19-2010, 11:14 AM	#8
jmanthony65 Registered User Join Date: Aug 2008 Location: Nacogdoches,TX Posts: 57	Re: Turbo 350 problem... The fluid did not look or smell bad. As far as I can tell the engine braking is normal. It has started to make a noise when shifting into reverse not really a grinding sound more like a light crackling sound.. I'm at a loss so any help will be welcomed. I dont really know much about transmissions so where would I put the pressure gauge?



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