Driveshaft! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

fufanu180 · 03-08-2010, 07:09 AM

This weekend I did a motor swap and everything went well except the driveshaft. The KA driveshaft won't button up to the SR tranny so smoothly. There is about 1 1/2 inches that still pertrudes from the transmission and the damn thing just won't go in any further.

It also doesn't help that I have a J30 diff that is 3/4 of an inch longer than that of the original KA diff.

What would be my possible solutions?

Is there any way I could come a cross an SR yoke that would slide in the butt of the tranny just right?

fufanu180 · 03-08-2010, 08:22 AM

Come on guys this is the only thing keeping me from being able take my 240 for a drive. =[

fufanu180 · 03-08-2010, 08:38 AM

Is there any difference between the SR driveshaft or the KA driveshaft?

Length? or anything?

jim1234664 · 03-08-2010, 08:48 AM

i think you have to pound a dust collar out of the sr tranny so the KA driveshaft can slide in all the way or something? look for an sr20 swap write up

projectRDM · 03-08-2010, 09:11 AM

SR vs KA are the same length, the only difference is ABS vs non ABS. If the dust collar has been removed you will see some of the shaft visible when installed, it's not meant to sit flush against the tail section. If it did you'd wear the rear seal out in a few hundred miles.

Maybe a picture might help, but a small amount of visible spline section is normal.

fufanu180 · 03-08-2010, 12:48 PM

would the extra visible shaft be the cause of possible leaks at the rear output seal cause in reality there is nothing holding it in place.

Now that I think this is settled my next problem is that I replaced the old diff with a j30 diff. The diff is .75 inches longer than that of the stock shaft. the drive shaft won't line up now because the length from the ouput shaft to the diff is shorter than the actual driveshaft.

projectRDM · 03-08-2010, 01:19 PM

The seal doesn't care where the driveshaft sits, as long as it's tight against it. It's pressed into the tail section, so it is held in place. It does not need to sit flush against the flange though, that will wear. Look at a crank seal, the crank sticks out past the seal a little, but the tension from the seal keeps it tight on the crank as it rotates. The driveshaft is the same way, the seal just fits snug around it, but if the shaft is too long the flange sits flat against the seal's facing edge, this will chew it up and cause leaks.

The J30 diff is an ABS unit, so you would need the shorter ABS driveshaft, though there are tons of threads on here, many I've replied to, where people have successfully used the non ABS shaft, it's just a tighter fit. The overall drivleine can be adjusted a hair between the crossmember, engine and transmission mounts, subframe, and diff mounts. I ran a non ABS shaft with an ABS diff for over eight years in my second car and it never wore on the seal, but the same setup swapped into my third car was too tight and I had to get the driveshaft shortened a bit. You may find you can make some room by playing with the mounting points of everything in the car, but if not you will need the shorter driveshaft so that it doesn't fit tight against the transmission's tail and wear the seal and housing.

fufanu180 · 03-08-2010, 08:10 PM

Quote:

Originally Posted by projectRDM

The seal doesn't care where the driveshaft sits, as long as it's tight against it. It's pressed into the tail section, so it is held in place. It does not need to sit flush against the flange though, that will wear. Look at a crank seal, the crank sticks out past the seal a little, but the tension from the seal keeps it tight on the crank as it rotates. The driveshaft is the same way, the seal just fits snug around it, but if the shaft is too long the flange sits flat against the seal's facing edge, this will chew it up and cause leaks.

The J30 diff is an ABS unit, so you would need the shorter ABS driveshaft, though there are tons of threads on here, many I've replied to, where people have successfully used the non ABS shaft, it's just a tighter fit. The overall drivleine can be adjusted a hair between the crossmember, engine and transmission mounts, subframe, and diff mounts. I ran a non ABS shaft with an ABS diff for over eight years in my second car and it never wore on the seal, but the same setup swapped into my third car was too tight and I had to get the driveshaft shortened a bit. You may find you can make some room by playing with the mounting points of everything in the car, but if not you will need the shorter driveshaft so that it doesn't fit tight against the transmission's tail and wear the seal and housing.

Thank you for the information. I am thinking about just going out and buying an ABS driveshaft and seeing if it will button up, atleast before I go cutting driveshafts.

If somehow I can make the driveshaft that I have right now work but it's just a tight fit, will that mess anything up? I'm nervous that if it try hard enough to get in the driveshaft that I will end up getting that yoke stuck in tail end of the tranny, in turn making it nearly impossible to take out again.

03-08-2010, 07:09 AM	#1
fufanu180 Zilvia Junkie Join Date: Dec 2009 Location: Austin, Tx. Age: 30 Posts: 481 Trader Rating: (12) Feedback Score: 12 reviews	Driveshaft! This weekend I did a motor swap and everything went well except the driveshaft. The KA driveshaft won't button up to the SR tranny so smoothly. There is about 1 1/2 inches that still pertrudes from the transmission and the damn thing just won't go in any further. It also doesn't help that I have a J30 diff that is 3/4 of an inch longer than that of the original KA diff. What would be my possible solutions? Is there any way I could come a cross an SR yoke that would slide in the butt of the tranny just right?

03-08-2010, 09:11 AM	#5
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	SR vs KA are the same length, the only difference is ABS vs non ABS. If the dust collar has been removed you will see some of the shaft visible when installed, it's not meant to sit flush against the tail section. If it did you'd wear the rear seal out in a few hundred miles. Maybe a picture might help, but a small amount of visible spline section is normal. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

03-08-2010, 01:19 PM	#7
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	The seal doesn't care where the driveshaft sits, as long as it's tight against it. It's pressed into the tail section, so it is held in place. It does not need to sit flush against the flange though, that will wear. Look at a crank seal, the crank sticks out past the seal a little, but the tension from the seal keeps it tight on the crank as it rotates. The driveshaft is the same way, the seal just fits snug around it, but if the shaft is too long the flange sits flat against the seal's facing edge, this will chew it up and cause leaks. The J30 diff is an ABS unit, so you would need the shorter ABS driveshaft, though there are tons of threads on here, many I've replied to, where people have successfully used the non ABS shaft, it's just a tighter fit. The overall drivleine can be adjusted a hair between the crossmember, engine and transmission mounts, subframe, and diff mounts. I ran a non ABS shaft with an ABS diff for over eight years in my second car and it never wore on the seal, but the same setup swapped into my third car was too tight and I had to get the driveshaft shortened a bit. You may find you can make some room by playing with the mounting points of everything in the car, but if not you will need the shorter driveshaft so that it doesn't fit tight against the transmission's tail and wear the seal and housing. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

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03-08-2010, 08:22 AM	#2
fufanu180 Zilvia Junkie Join Date: Dec 2009 Location: Austin, Tx. Age: 30 Posts: 481 Trader Rating: (12) Feedback Score: 12 reviews	Come on guys this is the only thing keeping me from being able take my 240 for a drive. =[

03-08-2010, 08:38 AM	#3
fufanu180 Zilvia Junkie Join Date: Dec 2009 Location: Austin, Tx. Age: 30 Posts: 481 Trader Rating: (12) Feedback Score: 12 reviews	Is there any difference between the SR driveshaft or the KA driveshaft? Length? or anything?

03-08-2010, 08:48 AM	#4
jim1234664 Zilvia Member Join Date: Nov 2004 Location: Buffalo, NY Posts: 227 Trader Rating: (1) Feedback Score: 1 reviews	i think you have to pound a dust collar out of the sr tranny so the KA driveshaft can slide in all the way or something? look for an sr20 swap write up

03-08-2010, 12:48 PM	#6
fufanu180 Zilvia Junkie Join Date: Dec 2009 Location: Austin, Tx. Age: 30 Posts: 481 Trader Rating: (12) Feedback Score: 12 reviews	would the extra visible shaft be the cause of possible leaks at the rear output seal cause in reality there is nothing holding it in place. Now that I think this is settled my next problem is that I replaced the old diff with a j30 diff. The diff is .75 inches longer than that of the stock shaft. the drive shaft won't line up now because the length from the ouput shaft to the diff is shorter than the actual driveshaft.