700r4 question. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

k5b · 03-03-2005, 05:52 PM

When in drive and I slow down to stop the downshift to first gear is kind of hard,when in overdrive and i slow to stop you can hardly feel the down shift.Why does it do this? is this normal?

1974gmc · 03-03-2005, 06:03 PM

i get the same thing with my th350, jerks relly hard goin into 1st

truckinbean · 03-03-2005, 09:45 PM

I've noticed the exact same thing on my 700r4. I hope it doesn't mean my trans is going to go out on me.

8t5Silverado · 03-03-2005, 10:44 PM

I've got it too.

magnethead · 03-04-2005, 12:21 AM

haven't noticed it yet in the 700R4 in the camaro, but the TH400 in the dually has a hard upshift to third and mildly hard downshift to 1st.

86-C10-V6 · 03-04-2005, 06:37 PM

My 700R4 has operated this way since it was new.

1985K10 · 03-05-2005, 01:48 AM

I think the hard downshift is because in drive you're tranny will act like an engine brake. For example, if you're going down a hill with you're foot off the brake it should feel like theres something holding the truck back from coasting. As soon as you put it in OD it will take off and coast, because the tranny is no longer "braking".

I'm sure this is normal, i think this is mentioned in the Owners(engine braking when in D vs. OD)

BTW, mine tranny does the same thing(700R4)

86k10 · 03-05-2005, 02:00 PM

How fast are you going when you feel this downshift happen. They all do it when in d3 and downshift to 2nd when coming to a stop, maybe that's what you're feeling instead.

plumbcut · 03-05-2005, 02:25 PM

if you have the shifter in any of the lower gears, it does something to the line pressures.. my th350's have always done this and im pretty sure my 700 does it too.. Its normal.. im not 100% sure of how or why it does it, but its normal

TrainD5115 · 03-05-2005, 04:44 PM

I don't know that I'd call it normal. My TH350 never did it until I developed a vacuum leak that still remains unfound. I replaced the vacuum line from the trans line to the manifold (small piece of hose about 1" long in front of distributer) and this helped some. Whatever is causing my engine to idle higher than normal is the root of the problem for my downshifting. I am leaning toward a faulty EGR block off but until I get around to getting another gasket for it I won't know for sure.

87_Blazer · 03-10-2005, 09:45 PM

ry greasing the splines on your transfer case's output shaft. i had the same thing happen downshifting from 2nd to first and also from first to second as well. Anyway I greased em up and slapped the d/s back in and it quieted it down a bit. Of course this isn't a permanent fix; but it should help a little bit.

k5b · 03-10-2005, 10:51 PM

Quote:

Originally Posted by 86k10

How fast are you going when you feel this downshift happen. They all do it when in d3 and downshift to 2nd when coming to a stop, maybe that's what you're feeling instead.

it happens when I slow down to about 10 mph.

apstguy · 03-11-2005, 02:07 AM

My old TH700 did that in drive. It is how they are.

87_Blazer · 03-11-2005, 05:28 PM

I also hear that GM has a "special" yoke that they sell that helps this. Turns out it is plated with somethng (nickel)?. It's cost is 125.00; but I'm not gonna go there......

MylilBowTie · 03-11-2005, 08:41 PM

I've got a shift kit (transgo) in my th400 and I cant even feel it down shift coming to a stop. Its very unnoticeable you can hear the rpms go up just a tad but other than that its really hard to notice.

Brad, have you checked to see if the transmission filter has more than one O-ring? I forget how the th350s are setup but on a th400 sometimes the old O-ring stays in the bore. When the other one gets installed there will be 2 O-rings now and it will cause a lot problems. Might want to check that out if nothing else works.

k5b · 03-11-2005, 10:39 PM

Quote:

Originally Posted by 87_Blazer

I also hear that GM has a "special" yoke that they sell that helps this. Turns out it is plated with somethng (nickel)?. It's cost is 125.00; but I'm not gonna go there......

me either.

86k10 · 03-12-2005, 01:28 AM

Quote:

Originally Posted by k5b

it happens when I slow down to about 10 mph.

If it happens at that high of speed it's 3-2. That is perfectly normal for them unless it is to harsh. It wont hurt anything, but if you want to fix it all you have to do is have your local machine shop take off about .125 off the inner hub of the second apply servo piston. They do it in D3 and not D4 because in D3 the overrun clutch is applied and that's responsible for your engine braking. In D4 it's not applied.

Sierra · 04-02-2005, 12:44 AM

Same here. My TH350 feels as though it is being manually downshifted into first gear, without benefit of a clutch. Severe clunk felt at 10 mph or less, on approaching a stop. No harm done so far, with 60K miles on it.

03-03-2005, 05:52 PM	#1
k5b Registered User Join Date: Sep 2004 Location: Bushkill,PA Posts: 38	700r4 question. When in drive and I slow down to stop the downshift to first gear is kind of hard,when in overdrive and i slow to stop you can hardly feel the down shift.Why does it do this? is this normal? __________________ 85 K5 Blazer

03-03-2005, 06:03 PM	#2
1974gmc In Progress Join Date: Feb 2005 Location: Kamloops, BC, Canada Posts: 312	i get the same thing with my th350, jerks relly hard goin into 1st __________________ 1993 Chevrolet K2500 454 4L80E 1974 GMC 1/2t 2wd Stepside 305 auto sold 1985 Ford Mustang GT 5.0 5spd

03-03-2005, 09:45 PM	#3
truckinbean Registered User Join Date: Jan 2005 Location: Strathmore, CA Posts: 110	I've noticed the exact same thing on my 700r4. I hope it doesn't mean my trans is going to go out on me. __________________ '77 Blazer 2wd lowered 5/6 Goodwrench 350/700r4/3.73 Performer intake Performer 1400 carb Sanderson Headers/Dual 2 1/2" Flowmasters

03-03-2005, 10:44 PM	#4
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	I've got it too. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

03-04-2005, 06:37 PM	#6
86-C10-V6 Shadetree Mechanic Join Date: Oct 2002 Location: Youngsville, NC Posts: 100	Normal My 700R4 has operated this way since it was new. __________________ Dave M. (Hacksaw) 86 C10 Scottsdale LWB, 4.3L, Edelbrock 1904, K&N, 700R4, 3.08 Auburn Performance 89 GMC S-15 Extended Cab 4x4, 4.3L, FI 98 K1500 Xcab, 5.7L, 3.43 Gov-Lok

03-04-2005, 12:21 AM	#5
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	haven't noticed it yet in the 700R4 in the camaro, but the TH400 in the dually has a hard upshift to third and mildly hard downshift to 1st.

03-05-2005, 01:48 AM	#7
1985K10 Registered User Join Date: Oct 2003 Location: CT Posts: 315	I think the hard downshift is because in drive you're tranny will act like an engine brake. For example, if you're going down a hill with you're foot off the brake it should feel like theres something holding the truck back from coasting. As soon as you put it in OD it will take off and coast, because the tranny is no longer "braking". I'm sure this is normal, i think this is mentioned in the Owners(engine braking when in D vs. OD) BTW, mine tranny does the same thing(700R4) __________________ Anthony 07 Tahoe LT 70 Chevelle 450HP 383-TH400 77 GMC Royal Sierra~Resto in progress~

03-05-2005, 02:00 PM	#8
86k10 Registered User Join Date: Feb 2003 Location: Bertrand, Nebraska Posts: 355	How fast are you going when you feel this downshift happen. They all do it when in d3 and downshift to 2nd when coming to a stop, maybe that's what you're feeling instead. __________________ 98 Neon 97 Grand Prix GT 02 Grand Prix 40th Anniv. 86 GMC 5.0 77 Olds 98 6.6 REAL AMERICANS, DRIVE AMERICAN

03-05-2005, 02:25 PM	#9
plumbcut california fill Join Date: Apr 2004 Location: Sunny So-Cal Posts: 694	if you have the shifter in any of the lower gears, it does something to the line pressures.. my th350's have always done this and im pretty sure my 700 does it too.. Its normal.. im not 100% sure of how or why it does it, but its normal

03-05-2005, 04:44 PM	#10
TrainD5115 North Coast, baby! Join Date: Jun 2004 Location: Toledo, OH Posts: 437	I don't know that I'd call it normal. My TH350 never did it until I developed a vacuum leak that still remains unfound. I replaced the vacuum line from the trans line to the manifold (small piece of hose about 1" long in front of distributer) and this helped some. Whatever is causing my engine to idle higher than normal is the root of the problem for my downshifting. I am leaning toward a faulty EGR block off but until I get around to getting another gasket for it I won't know for sure. __________________ Brad 79 Scottsdale C20 350/350 3.73's Still running full CA smog gear!

03-10-2005, 09:45 PM	#11
87_Blazer Getcha' Pull!!! Join Date: Jun 2004 Location: Jim Thorpe, Pennsylvania Posts: 215	ry greasing the splines on your transfer case's output shaft. i had the same thing happen downshifting from 2nd to first and also from first to second as well. Anyway I greased em up and slapped the d/s back in and it quieted it down a bit. Of course this isn't a permanent fix; but it should help a little bit.

03-11-2005, 02:07 AM	#13
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,088	My old TH700 did that in drive. It is how they are. __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

03-11-2005, 05:28 PM	#14
87_Blazer Getcha' Pull!!! Join Date: Jun 2004 Location: Jim Thorpe, Pennsylvania Posts: 215	I also hear that GM has a "special" yoke that they sell that helps this. Turns out it is plated with somethng (nickel)?. It's cost is 125.00; but I'm not gonna go there......

03-11-2005, 08:41 PM	#15
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	I've got a shift kit (transgo) in my th400 and I cant even feel it down shift coming to a stop. Its very unnoticeable you can hear the rpms go up just a tad but other than that its really hard to notice. Brad, have you checked to see if the transmission filter has more than one O-ring? I forget how the th350s are setup but on a th400 sometimes the old O-ring stays in the bore. When the other one gets installed there will be 2 O-rings now and it will cause a lot problems. Might want to check that out if nothing else works. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI Last edited by MylilBowTie; 03-11-2005 at 08:47 PM.

04-02-2005, 12:44 AM	#18
Sierra Registered User Join Date: Nov 2000 Location: Victoria, Texas Posts: 71	Same here. My TH350 feels as though it is being manually downshifted into first gear, without benefit of a clutch. Severe clunk felt at 10 mph or less, on approaching a stop. No harm done so far, with 60K miles on it.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.