TH400 Driveshaft Question
 

I am replacing the exploded 350 trans with a 400 in my 85. I have noticed the trans yoke bolts to the output shaft on the 400 unlike the slider on the 350. How does this work? How does the shaft move when the suspension articulates? I need to figure this out before I get the driveshaft built.

Thanks,
Josh

Re: TH400 Driveshaft Question
 

you need a 2 piece driveshaft with carrier bearing out of a long wheel base truck. i have the same tranny in my swb truck and spent close to $400 to have a driveshaft built. if you need pics of my d/s let me know it has the "slip" built into the driveshaft. if you have a lwb truck, maybe you can find a driveshaft/carrier bearing setup in a salvage yard or from a board member.

Re: TH400 Driveshaft Question
 

Do you have a long or short bed truck?

The th400s bolt on yoke is for a two piece driveshaft.

Re: TH400 Driveshaft Question
 

There are special trans yokes available that will let you run a one-piece driveshaft with that transmission.

If you need a new driveshaft, I would recommend you look at http://www.dennysdriveshaft.com/. Their nitrous ready shafts are on sale this week... $30 off the normal price if you mention the ad on the website. I am getting ready to order one for my truck with a 4l80e. These come with the trans yoke and use the large 1350 U-joints. You would need a 1350 pinion yoke too... but Dennys has those as well.

Re: TH400 Driveshaft Question
 

Okay, so I can get a slip style shaft and have it shortened? We have a very reputable driveshaft company near where I work. I was going to have them do what they need to, to get a d/s to fit. If I have them use my old diff yoke, I could still use a U-joint for a 350 trans on the back end.

Josh

Re: TH400 Driveshaft Question
 

Slug,
I would like to see some pics if you don't mind. I would rather stay away from a slit driveshaft as I don't like the extra u joints and I don't have a mount for the carrier. I was thinking more of like the front d/s out of a 4wd truck. Would that work?

Josh

Re: TH400 Driveshaft Question
 

Well being that you have a short wheel base truck. You don't have to worry about a two piece driveshaft. If it was a long wheel base it would be different.

I believe all you need is a th400 slip yoke and measure for a new driveshaft. If you can swing it 1350 series u-joint would be stronger. U-joints with 1350 and 1310 end aren't going to hold up any better than the stock size 1310 ones.

Re: TH400 Driveshaft Question
 

Okay. Ive found some slip yokes at Summit, and Jegs. I will still need a driveshaft from a 400 trans to get the mating yoke correct?

Josh

Re: TH400 Driveshaft Question
 

If that's the case then just call them up and tell them what you have. If they are competent, then they should know exactly how to build you a new d/s. All you should need to provide is the length from the tailshaft housing to the pinion yoke.

Re: TH400 Driveshaft Question
 

actually there were slip on and bolt on driveshafts. I was told the vans had bolt on driveshafts and the pickups had slide ons and that the bolt ons were the short tails and the slide ons were long tails.. I had a long tail th400 on my 86 that had a slide on
I dont remember the whole story but you could put a slide on yoke into a bolt on trans or something like that but i had gotten a good used longtail th400 when i needed one so i never bothered with the short tail

Re: TH400 Driveshaft Question
 

i dont think you can go and put a slip type yolk on the bolt on tranny. there is not enough room for the yolk to slide in the tranny. try unbolting the yolk and slide it off, you'll see what i mean.i'll try and get a pic of the d/s this evening when i get home.

Re: TH400 Driveshaft Question
 

That is just what I was thinking. This is a short tail. There can't be more than a couple inches of spline ingagement when its pushed all the way on. I think Im stuck with the bolt on. I'll try to find a slip shaft off of a 400 longbed. I can take that to the D/S shop and have it modified.

Josh

Re: TH400 Driveshaft Question
 

From the Dennys site I posted earlier -

Why reinvent the wheel?

Re: TH400 Driveshaft Question
 

im not sure that why i worded it like i did and the guy who told me was the guy in my local boneyard who was selling the transmission in the first place

Re: TH400 Driveshaft Question
 

Josh, Try To Get As Much Of The 2 Piece D/s As You Can, Even The Carrier Bearing. I Didnt Have Anything From The 2 Piece Set Up, Thats Why It Cost So Much To Have The D/s For The Swb Made

Re: TH400 Driveshaft Question
 

Greg,
Where did you get that? Also, are all 1310, 1350 u-joints measure the same? What is a stock u-joint? Im curious if the driveshaft yoke from say a 350 trans will use the same u-joint as a 1310, or whatever a stock 400 yoke is.

You guys are awesome.

Josh

Re: TH400 Driveshaft Question
 

Th400 in your 86 was th375. It has a smaller output shaft than the th400. The transmission cases are the same. The length of the output shaft is longer also.

I'm pretty sure all he needs to do is buy a slip yoke. Then have the driveshaft made the correct length. Looking at his other post you will see why he needs a th400. That is why I agreed with the 1350 u-joint upgrade if he can.

Long beds use mostly two piece driveshafts because of the length. You don't have to worry about that with the short bed. Its well within the normal length to build a one piece driveshaft.

Depending on the Vans transmission it could have either two piece or single driveshaft.

Re: TH400 Driveshaft Question
 

What is the difference between 1310, 1330 and 1350 Series?
The "series" of a driveshaft or universal joint is determined by the actual dimensions of the u-joint. While the front and rear u-joint can be of two different sizes the shaft is only as strong as the smaller one. The 1310 series u-joint measures approximately 3 1/4 inches wide. The 1330 and 1350 both measure approximately 3 5/8 wide. The 1310 and 1330 series can have cap diameters of 1 1/16 and/or 1 1/8 inch or a combination of both sizes. The 1350 series has a cap diameter of 1 3/16 inch and the body and journals are bigger than the 1310 or 1330. Remember 1350 is almost never found in production car driveshafts.

Re: TH400 Driveshaft Question
 

Haha... that's a quote from the FAQ page on the Dennys website

Here is the slip yoke page

Re: TH400 Driveshaft Question
 

Measuring based on the diagram at bottom, you should obtain one of the
following pairs of measurements for "E" and "D."

• E = 3-7/32" D = 1-1/16" (1310)
• E = 3-7/32" D = 1-1/8" (Ford 8”)
• E = 3-5/8" D = 1-1/16" (1330)
• E = 3-5/8" D = 1-1/8" (Ford 9”)
• E = 3-5/8" D = 1-3/16" (1350)

Re: TH400 Driveshaft Question
 

I was trying to find one with the exact dimensions but couldn't find it. I think Randy's Ring and pinion used to have it. The second one is from Inland Empire.

If it makes any difference I have a two piece drive shaft. Its from a HD 3/4 ton that had a short tail th400 and 14 bolt ff rear.

Re: TH400 Driveshaft Question
 

The 400s that had bolt in tailshafts have a different length than do the short shafts trans such as found in a Chevelle/GTO. If you had a TH350 in your truck you had the longer tailshaft housing on it, it just so happens that the shortshaft 350,400, 2004R, and 700R4 are all the same length. I know I was amazed as well, but having them all sitting side by side in the shop it was readily apparent. The bolt ons are slightly longer than the car shafts, the thread engagement isnt a problem with a slip on 400 yoke, they are all pretty short.

The bolt on, as said earlier is for the two piece shaft with the carrier bearing. If you use that yoke without the bolt, you will leak trans fluid from it, as there is nothing holding fluid in at that point. but other than the bolt hole there isnt much difference in the bolt on and slip on yokes.

Can get pics of all the transmissions if you need clarification. Even a long shaft th350. I really should be in the shop right now anyway.. maybe I will take the camera out there when i fix the beater.

Re: TH400 Driveshaft Question
 

The slip yoke might be the same length but the transmissions are not.

A slip yoke out of a th350,700r4,200r4 will not fit a th400. They will fit a th375 that has a smaller diameter output shaft and 27 spline count. Short tail th400 have 32 spline count and is bigger in diameter bolt on yoke or slip.

85 C-10's Truck if it had a th350 would be a 6in tailshaft version. Because his truck is a short bed, shortwheel base. Long beds got the 9in tailshaft version of the th350.

Im pretty sure the the stock u-joint for your truck is the 1310 size. If you measure your u-joint using the chart. That will tell you what size u-joint you have.

Re: TH400 Driveshaft Question
 

Okay guys, you are clearing up a lot for me. I want a Denny's D/S. Problem I have is the budget the accountant gave me. I have $1500 spend. $1000 is gone to trans and converter. I think for now I will get a 400 slip yoke, use both ends of my busted shaft and have the local place re-shaft it. This summer I will look at getting a Denny's shaft. I don't think the local shop is as good as Dennys. The engine is only making maybe 300hp or so. I think the trans was weak and let go, which took out everything else. I need new mufflers, starter, tranny lines, shifter linkage, dipstick, and some little things for the 400 kickdown. I think I may bargain witht he wife for a little more $$!

Josh

Re: TH400 Driveshaft Question
 

:devil:

THIS IS MY SETUP. THE SHAFT UNDER THE YOLK HAS SPLINES LIKE A AXLE AND HAS THE YOLK SLIDE OVER THE SHAFT. IM SURE ONE OF THOSE CONVERSION YOLKS WOULD WORK JUST AS GOOD, BUT AT THE TIME I DIDNT KNOW THEY EVEN MADE THEM, AND THIS IS WHAT I HAD MADE