cdnturboz

iTrader: (3)

I have a 95 firebird formula with a 5.7 Lt1 6spd. I got the car from a kid who messed around removing the driveshaft and messed up the rear ujoint. This driveshaft is aluminum. Which I thought all lt1 cars came stock with steel shafts..

I was going to put it back together and ordered a new ujoint. The new one I got will not fit. I went into the shed and checked a steel fbody driveshaft that I have and the new ujoint fits much better.

Is there a difference in ujoints between the aluminum and steel driveshafts?

Also the aluminum driveshaft has a date on it of August 96....Is there a different year of fbody that I should be telling the parts guy when I order the ujoints?

96lt4c4

iTrader: (5)

I think the early LT1 SS cars had a different aluminum drive shaft than the standard LS1 drive shaft. My friends 96 SS has a different shaft then my 99 LS1 SS. His seems to be heavier duty than mine. I would say you have a better drive shaft than the normal LS1 shaft. I am guessing SLP had these made until GM started putting in thier version which sucks and breaks. As far as getting a joint for yours I have no idea

dlandsvZ28

The first question to answer is if you have the stock rearend or an aftermarket rearend (Moser or Strange)? If so, you will need a conversion joint. Most aftermarket rearends come with a 1350 yoke which is bigger than the yoke on a stock driveshaft. The conversion joint matches the smaller yoke with the larger yoke.

Search this forum 'conversion u joint'. The results perhaps better explain what is needed than my explanation.

The link below shows the difference. The part number is NEA 2-1153. I got mine at Advance Auto.

http://www.thirskauto.com/vehicle-re...ea_2-1153.html

All driveshafts 95-2002 are the same length whether the transmission is a manual (M6) or automatic (A4). Some aluminum driveshafts have a sticker on them with "Three Rivers". Even so they are still stock driveshafts made for GM.

As for the length of the driveshaft required if you have an aftermarket rearend. If it is a Moser 12 bolt, the length will be the same. With other brands it might be different.

I suppose its possible that you have an aftermarket driveshaft that has 1350 yoke but you still have a stock rearend end. You will still need a conversion ujoint to match the larger yoke on the driveshaft with the smaller yoke on the stock rearend. The part number is still the same provided of course that the yoke on the driveshaft is a 1350.

cdnturboz

iTrader: (3)

Thanks for the reply, as far as I know the rear end looks stock, etc. Its the driveshaft and yoke that goes into the transmission that seems slightly smaller than the steel one.

I'll have to look into those part numbers

Thanks

dlandsvZ28

Your original post stated that the 'rear u joint was messed up' but now you are mentioning the front u joint and slip yoke. Which is it? Are you trying to replace the front u joint, the rear u joint, or both?

Obviously you have removed the aluminum driveshaft from the transmission. The stock aluminum driveshaft diameter is 3 inches. Its length is stated in the links below.

The link below contains information about the stock oem aluminum driveshaft.

https://ls1tech.com/forums/gears-axl...ft-length.html

http://www.camaroz28.com/forums/driv...estion-582323/

I can't find specs, but as I recall the steel driveshaft is 2.75 inches in diameter compared to the aluminum which is 3 inches in diameter. If so that explains why when you look at it that it appears to be smaller.

But when you state 'smaller', are you referring to the length of the front slip yoke and that it appears to be shorter (smaller) on the steel driveshaft compared to the length of the slip yoke on the aluminum driveshaft?

Or are you referring to the entire length (smaller) of the driveshaft including front slip yoke?

If you have removed the u joint from the aluminum driveshaft, take it with you so you can compare what you have to what the parts guy lays out on the counter. You measure end cap to end cap as well as the diameter of the end caps.

When you go to the parts store, you will be asking for the u joint for a 1998-2002 not a 1995 since you no longer have a 1995 driveshaft. You have a 1998 - 2002 driveshaft Z28 or SS (not a V6 which came with a steel driveshaft during the same time period). Neapco and Spicer are good brand names for u joints. Advance Auto or Napa are excellent sources for u joints and carry brand names vs house brand (which might be China stuff).

https://ls1tech.com/forums/gears-axl...-u-joints.html

Tip: When you tighten the end cap retainers on the rear of the driveshaft - tighten the bolts evenly - don't clamp one side down and then the other. Don't over torque them either.

hth

01ssreda4

iTrader: (96)

Why don't you post a pic of what you have so we can help you. Obviously you don't know what you are looking at, so maybe a pic would get some guys to chime in that do know more about driveshafts

NAMYZZO

..all driveshafts are not the same..
there are 3 styles.. v6 with a 2PC, a steel shaft and an aluminum shaft..
the 2 single piece driveshafts come in 2 lengths..1 @ 40 7/8"C-C and 1 @ 41 1/2"C-C.
The 2 uj style driveshafts made are different lengths because of different length slip yokes used by the shaft manufacturers - and maybe becuase of the type of seal used on the transmission - or possibly a difference in auto OR manual (not sure yet)...Slip yokes used vary in length,fully splined or counterbored..
..if you use a 40 7/8"C-C and have to replace the slip yoke with the standard th350 slip @ 5.5"L = it will be shorter than the ideal length..the slip would only actually engage in the transmission about 2".. ideally it should be 2 5/8"

pn#'s I have seen..They may be steel or aluminum..
12560725, 12559525, 12554454

yah - they will all interchange.. just thought i'd share the differences I know about..
Also there are differences in the trans seal..one is flat and the other is "booted"..So using the shorter shaft - with the flat seal = make make it appear that the shaft is too short and is hanging out too far from the seal..

just fyi...

DCL-1970

I have a 1994 Z28 w/6-speed M.T. The 2.5" dia. steel drive shaft measures 40 13/16" or 40.8" (c/c u-joints). This measurement agrees with the MVMA Specifications for the 1994 Camaro w/5.7L eng. & 6-speed M.T. (2.5 X 40.8 X .065 in.)

I bought a nice 3.0" dia. aluminum 1999 Camaro drive shaft at a swap meet in Connecticut. The aluminum drive shaft has a sticker "Three Rivers 12559525 AA" and measures 40 7/8" or 40.9" (c/c u-joints). The MVMA Specifications for the 1999 Camaro drive shaft w/5.7L eng. & 6-speed M.T. are 3.0 X 40.9 X .083 in.

I plan to install the alum. driveshaft next Spring. Hopefully the slip yokes will be the same length or very close. The yoke on the alum. drive shaft measures about 6.1" (center of u-jt. to end), total length of driveshaft would be 40.9" + 6.1" = 47.0" (center of u-jt. to end of yoke).

Dave

01ssreda4

iTrader: (96)

LT and LS driveshafts do interchange without issue. Got a buddy running an LS M6 aluminum DS on his LT1/auto car.

Jezus Ramirez

Jezus Ramirez