Where did that crossmember come from! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jlaird · 05-02-2007, 07:56 PM

Got my truck down on the ground today. Its sitting on the crossmember that is right in front of the cab. I totally overlooked that sucker. So what is everybody doing with this thing. I just looked at a couple builds, and they have been removed. Is it ok to take it out?

crazy longhorn · 05-02-2007, 08:06 PM

If you are running an auto trans, chop that bell mount crossmember out....you dont need it. In fact, the 3 spd stick(saginaw trans) will bolt right down on the auto crossmember.....

L

jlaird · 05-02-2007, 08:12 PM

so that crossmember is for manual tranny mounting? I have an auto, but was thinking about going manual.

FRENCHBLUE72 · 05-02-2007, 09:21 PM

mine ran away when the torch came out..

jlaird · 05-02-2007, 10:12 PM

Quote:

Originally Posted by FRENCHBLUE72

mine ran away when the torch came out..

LOL! I'll have to get the 'ol sawzall out tomorrow.

lowrollin70gmc · 05-03-2007, 12:14 PM

Real hot rods have three pedals.

But seriously, the 3 speed will bolt up to an auto x-member? I may have to do that when I lay her out.

1lowdiesel · 05-03-2007, 01:48 PM

yup

jlaird · 05-03-2007, 02:36 PM

What's the difference that makes a manual tranny need the mounts and an auto not needing the mounts?

jsbgump · 05-03-2007, 05:24 PM

The manual tranny mount to the frame using the bell housing. While the auto tranny uses the pad back by the tailshaft of the tranny to mount to it's crossmemeber

SCOTI · 05-03-2007, 06:43 PM

The factory used the bellhousing style trans crossmembers on early trucks when the 3/4spds were very short. Once the trannys got longer (and heavier), they started using the same crossmember for both autos & standards which mounted under the tailshaft to better support the extra weight.

I was told by an old work buddy (who was a GM tech in the mid 70's), it's not recommended to run the longer manual trans w/the bellhousing style c.member.

dirtball · 05-03-2007, 09:24 PM

I was having fitment problems with my bellhousing crossmember and 3 speed. I decided to ditch it and make a tail housing mount crossmember. This is still in the fab. stage.

cajundragger · 05-03-2007, 10:08 PM

I hate when stuff pops out of no where. I know on my brothers '72 they have parts of the frame near the middle of the chassis that are on the bottom of the "C" and are bent down...well those would have kept him about .5 inches off the rails so they were quicky torched out and filled with a straight piece...

pissonNOS · 05-03-2007, 10:29 PM

reading this thread was throwing me for a loop for a bit but I think I have it figured out now. If you originally had a 3 speed that cross member isnt there? and if you had an auto it was? what was making it confusing for me I think is that I ahve a 4 speed out of a car which is obviously alot smaller than the regualr truck 4 speeds am i correct?

SCOTI · 05-03-2007, 11:12 PM

Non synchronized trannys are (were) smaller. Pass car & lt. truck trannys are interchangeable so it's hard to say what's what as far as sizes.

I had a 64 swb w/a 350/Muncie 4spd & they didn't use the c.member. That was my first lesson (@ 16) about how much flex was in the drive-line w/o the rear c.member.

05-02-2007, 07:56 PM	#1
jlaird Senior Member Join Date: May 2004 Location: johnstown, NY Posts: 2,393	Where did that crossmember come from! Got my truck down on the ground today. Its sitting on the crossmember that is right in front of the cab. I totally overlooked that sucker. So what is everybody doing with this thing. I just looked at a couple builds, and they have been removed. Is it ok to take it out?

05-02-2007, 08:06 PM	#2
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Re: Where did that crossmember come from! If you are running an auto trans, chop that bell mount crossmember out....you dont need it. In fact, the 3 spd stick(saginaw trans) will bolt right down on the auto crossmember..... L __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

05-02-2007, 08:12 PM	#3
jlaird Senior Member Join Date: May 2004 Location: johnstown, NY Posts: 2,393	Re: Where did that crossmember come from! so that crossmember is for manual tranny mounting? I have an auto, but was thinking about going manual.

05-02-2007, 09:21 PM	#4
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	Re: Where did that crossmember come from! mine ran away when the torch came out.. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

05-03-2007, 12:14 PM	#6
lowrollin70gmc Too many projects Join Date: Mar 2004 Location: Fargo, ND land of the flat hills Posts: 1,147	Re: Where did that crossmember come from! Real hot rods have three pedals. But seriously, the 3 speed will bolt up to an auto x-member? I may have to do that when I lay her out. __________________ Andrew 84 GMC C1500 SWB 6.2 Diesel/700R4/3.42 "Grandpa's odd duck" 70 GMC C1500 LWB My first truck: shaved, bagged, and more: the lowrollin70gmc 68 K20 Suburban 12V Cummins/NV5600/NP205/D60/11.5AAM 3.73s "Dakota Cadillac" 63 Chevy II Nova Coupe 250 I6/T56/4.56s "Economy car" 53 Willys Wagon 350/NV4500/BW4401/HP D44/9inch “Winter Wagon” 30 Model A 16 Focus ST

05-03-2007, 01:48 PM	#7
1lowdiesel Senior Member Join Date: Oct 2006 Location: central jersey Posts: 763	Re: Where did that crossmember come from! yup __________________ 69 4wd V6 20k orig miles!! 05 ccsb 2wd Diesel 500hp bagged and soon to be stock floored. 01 rcsb chevy 2wd 6bt cummins :devil:> build xtremediesel.com

05-03-2007, 02:36 PM	#8
jlaird Senior Member Join Date: May 2004 Location: johnstown, NY Posts: 2,393	Re: Where did that crossmember come from! What's the difference that makes a manual tranny need the mounts and an auto not needing the mounts?

05-03-2007, 05:24 PM	#9
jsbgump Gone Fishing Join Date: Aug 2005 Location: Fort Worth, Texas 76135 Posts: 12,361	Re: Where did that crossmember come from! The manual tranny mount to the frame using the bell housing. While the auto tranny uses the pad back by the tailshaft of the tranny to mount to it's crossmemeber __________________ 68 Chevy Short Fleetside LSX Swap Under Way 3.73 posi 2.5/4 drop Frame of resto has been started 2022 Hyundai Tucson Limited 2019 Chevy Traverse Redline Edition Wifes Ride Build Thread http://67-72chevytrucks.com/vboard/s...=1#post3483616

05-03-2007, 06:43 PM	#10
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,066	Re: Where did that crossmember come from! The factory used the bellhousing style trans crossmembers on early trucks when the 3/4spds were very short. Once the trannys got longer (and heavier), they started using the same crossmember for both autos & standards which mounted under the tailshaft to better support the extra weight. I was told by an old work buddy (who was a GM tech in the mid 70's), it's not recommended to run the longer manual trans w/the bellhousing style c.member. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.* Last edited by SCOTI; 05-03-2007 at 06:44 PM.

05-03-2007, 09:24 PM	#11
dirtball Registered User Join Date: May 2006 Location: Colorado Posts: 412	Re: Where did that crossmember come from! I was having fitment problems with my bellhousing crossmember and 3 speed. I decided to ditch it and make a tail housing mount crossmember. This is still in the fab. stage.

05-03-2007, 10:08 PM	#12
cajundragger Registered User Join Date: Aug 2006 Location: louisiana Posts: 1,008	Re: Where did that crossmember come from! I hate when stuff pops out of no where. I know on my brothers '72 they have parts of the frame near the middle of the chassis that are on the bottom of the "C" and are bent down...well those would have kept him about .5 inches off the rails so they were quicky torched out and filled with a straight piece...

05-03-2007, 10:29 PM	#13
pissonNOS senior member Join Date: Feb 2003 Location: fort macleod alberta Posts: 2,770	Re: Where did that crossmember come from! reading this thread was throwing me for a loop for a bit but I think I have it figured out now. If you originally had a 3 speed that cross member isnt there? and if you had an auto it was? what was making it confusing for me I think is that I ahve a 4 speed out of a car which is obviously alot smaller than the regualr truck 4 speeds am i correct? __________________ 69 GMC bagged

05-03-2007, 11:12 PM	#14
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,066	Re: Where did that crossmember come from! Non synchronized trannys are (were) smaller. Pass car & lt. truck trannys are interchangeable so it's hard to say what's what as far as sizes. I had a 64 swb w/a 350/Muncie 4spd & they didn't use the c.member. That was my first lesson (@ 16) about how much flex was in the drive-line w/o the rear c.member. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

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