Slip yoke on a TH400 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**leddzepp** · 05-29-2010, 03:29 AM

I am at the point of putting in a driveshaft on my SWB project truck, and was wondering how much "slip" is needed on a TH400 mated to a 402? I have a factory 2 piece driveshaft from a SWB parts chassis that I mocked up (This is the correct TH400 yoke). I measured and there is 1 3/4" before the yoke bottoms out on the tailshaft housing. Here is a pic to illustrate. Yep, I plan on replacing the u-joints too

Thank you in advance.

rsavage · 05-29-2010, 06:48 AM

If you are using a two piece shaft, the front section stays static and is located by the carrier bearing. The back section slides on the spline joint mating the two pieces as the axle moves up and down. Therefore, I don't think you need much travel for your front (transmission) yoke. I had about 3/8" on my 200 4R install and it seems to be fine. Someone else I'm sure will pipe in.

72freak · 05-29-2010, 09:22 AM

I think they say 3/4 to 1 inch of travel, however I doubt 1 1/4" would be a problem.

Duncan and son · 05-29-2010, 09:57 AM

Quote:

Originally Posted by 72freak

I think they say 3/4 to 1 inch of travel, however I doubt 1 1/4" would be a problem.

That is correct, rule of thumb we always use 1 inch. Most of the time the inside (the teeth) are fine but alot of folks never check the outside surface. If you can see or feel grooves you would be better to replace as the smallest wear will produce a vibration. New ones are about $65.
Hope that helps Paul and Jason

**leddzepp** · 05-29-2010, 12:28 PM

Well, it looks like I am good to go then

The carrier bearing has some adjustability as to where it mounts on the x-member. I had it in the "middle" in this pic. I can slide it forward a small amount, and that would give me exactly one inch of travel. The slip yoke has no wear on the outside and it drove great with no driveline vibrations when it was in use a few months ago on my LWB truck.

Thanks for the input guys!

Duncan and son · 05-29-2010, 01:48 PM

Ledd,I forgot to tell you 402/400 is music to my ears

**leddzepp** · 05-31-2010, 11:29 PM

Quote:

Originally Posted by Duncan and son

Ledd,I forgot to tell you 402/400 is music to my ears

Me too

This one has been freshened up and ready to go.

05-29-2010, 03:29 AM	#1
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,996	Slip yoke on a TH400 I am at the point of putting in a driveshaft on my SWB project truck, and was wondering how much "slip" is needed on a TH400 mated to a 402? I have a factory 2 piece driveshaft from a SWB parts chassis that I mocked up (This is the correct TH400 yoke). I measured and there is 1 3/4" before the yoke bottoms out on the tailshaft housing. Here is a pic to illustrate. Yep, I plan on replacing the u-joints too Thank you in advance. Attached Images __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man

05-29-2010, 06:48 AM	#2
rsavage Registered User Join Date: Aug 2009 Location: Alden NY Posts: 2,705	Re: Slip yoke on a TH400 If you are using a two piece shaft, the front section stays static and is located by the carrier bearing. The back section slides on the spline joint mating the two pieces as the axle moves up and down. Therefore, I don't think you need much travel for your front (transmission) yoke. I had about 3/8" on my 200 4R install and it seems to be fine. Someone else I'm sure will pipe in. __________________ 1961 C1 Corvette 1959 El Camino 350 TPI, 9" 4 w disc 69 Blazer K5 - sold July '20 2021 Durango RT 5.7

05-29-2010, 09:22 AM	#3
72freak Rottenwood Garage Member Join Date: May 2005 Location: Marietta, Georgia Posts: 4,321	Re: Slip yoke on a TH400 I think they say 3/4 to 1 inch of travel, however I doubt 1 1/4" would be a problem. __________________ 2004 Chevrolet Suburban C1500 2001 Chevrolet 2500HD Crew 6.0 1999 Harley Davidson Electra Glide 1972 Chevrolet C-20 Custom Camper "Dump Truck" 1972 Chevrolet C-20 Suburban "Big Green" 1969 Chevrolet C-50 Wedge Hauler "Leonidis" 1966 C-10 2x4 short fleet 327 4 speed "Race Truck" 1952 Plymouth Cranbrook "Rican" (my grandfathers) 1931 Ford Model A Coupe "Black Beauty" 1930 Ford Model A truck "Club Cab" 4x4 Rottenwood Garage and Speed Shop.....where everything must be racy! *It's not just a hobby..It's a LIFESTYLE!!!* Thanks for nothing Barrett-Jackson You cant fix stupid or teach accountability! Time wasters, looky Lous and tire kickers are everywhere!

05-29-2010, 12:28 PM	#5
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,996	Re: Slip yoke on a TH400 Well, it looks like I am good to go then The carrier bearing has some adjustability as to where it mounts on the x-member. I had it in the "middle" in this pic. I can slide it forward a small amount, and that would give me exactly one inch of travel. The slip yoke has no wear on the outside and it drove great with no driveline vibrations when it was in use a few months ago on my LWB truck. Thanks for the input guys! __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man

05-29-2010, 01:48 PM	#6
Duncan and son Registered User Join Date: Sep 2009 Location: Lubbock Texas Posts: 1,049	Re: Slip yoke on a TH400 Ledd,I forgot to tell you 402/400 is music to my ears __________________ You can shear a sheep every year, but you can only skin it once The person dealing with facts is never at the mercy of the person dealing with theory 1972 Cheyenne Super 402 400 A/c bucket seat tilt custom camper Longhorn 1975 Silverado 454 Crew cab camper special dually



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