ok i know you can put the Ls1 spindles on an LT1 car but cxan u put LT1 spindles on a LS1 car? they look exactly the same so i am just curious.
Thanks in advance
Justin

 

To answer the direct question, yes, they will fit the ball joints and bolt up, but your brake components WILL NOT fit. The LS1 spindle is VERY different from the LT1 spindle in that respect. So, unless you want to use an LT1 brake setup (your better off just opening the door and sticking your foot out to slow down), it will not work.

-Chris

 

huh?

Since when are early and late 4th gen spindles any different from each other? Everything I've read, heard, and even seen is that they are interchagable.

Exactly the same. They will bolt up, the ABS sensor is the same, and the hub/spindle and the lugs are the same.

What's different that makes the LS1-era cars unable to use a LT1-era spindle (other than the age of the LT1 spindles that may still be floating around)?

Now I'm confused.

 

ok now I get it.
Chris, the spindle/hub assembly is the rotating item that holds the wheel lugs, hub, and ABS sensor. It has 4 bolt holes on the mounting plate that holds it to the spindle arm.

I think you're talking about the spindle arm (the cast iron suspension piece that holds the hub assembly and mounts to the upper and lower A arms.

Yes, the hubs are interchangeable, and the spindle arms are not.

I'm not confused anymore.

 

Unfortunately, now the rest of us are.

 

While we're on the subject has anyone actually had an LS1 and LT1 spindle side by side and taken measurments?

Just curious because for some reason on my car with the LS1 brake upgrade I can get alot more negative camber than most people. Right now I'm at -1.1 on both sides and I could easily get more if I tried. My car isn't lowered either...

The only explination I can think of is that the LS1 spindle is 'slightly' different than the original LT1 piece. Unfortunately I never bothered to get an alignment with my stock brakes so I can't make a valid before/after comparison.

 

let me clarify... the spindle (aka hub) is exactly the same. The hub/spindle is about 6" square and mounts to the spindle arm (the big Y-shaped cast-iron arm that mounts to the lower and upper A arms) with 4 bolts.

The spindle arm DOES need to be swapped out during an LS1 upgrade, but you can remove and install your original LT1 hubs/spindles if the upgrade kit that you bought has a shot hub (like mine did).

all clear?

As for the LS1 spindle arm, I dunno, havn't really noticed or heard anything about increased camber ability... maybe the bushings aren't as tight or slightly worn already? It seems strange that GM would change the A arms and Spindle arm in the LS1 years to get the same capabilities as the LT1-era cars had. Could have happened I guess... I just wouldn't count on it. If the stock LT1 and stock LS1 cars individually had different camber abilities I suppose that would be possible, but seeing how stock setups seem the same, I'd wager the upgrade camber comes from using worn bushings or someother non-GM reason.

 

Well GM does lots of weird stuff

I just comparted the part numbers of the upper and lower A-arms for the LT1 cars vs the LS1 cars.

The upper A-arms are the same 93-01, unless it was a 1LE car or had the FE7 suspension (whatever that is). For some reason the 02 cars are different and they only use one version regardess of the suspension option.

Unforunately I can't make heads or tails of the lower control arm part numbers. There are about 15 different numbers and some of them seem to conflict with each other. They do seem to be grouped into two general categories though, one for the LT1 cars and one for the LS1 cars.

In conclusion I am even more confused than when I started. Maybe the difference is in the A-arms, maybe it isnt. All I know is GM must like building lots of seemingly identical parts for no obvious reason.

 

lol... this is getting stupid. Oh well... maybe they had a reason (like giving us 4th gen guys one last factory tweak to hold us over until the 5th gen arrives ).

hmmmm... interesting though.

This may be just a P/N change to document how the arms hold up in different factory set ups. The A4 and M6 driveshafts are a similar example. The A4 and M6 drive shafts are exactly the same, although GM uses a unique driveshaft number for each set up (supposedly in a effort to track if DS failures are unsually high in one set up or another).

From stories such as this, I've been led to belive that Part Numbers are used by GM as product feedback, inaddition to inventory/production we normally assume they identify.

Now I guess the second step is to FIND and MEASURE dimentions of these diffent A-arm part numbers, to see if they are just marked differently, or if they are in fact dimentionally different.

I've got a '97 Trans Am I can check. Guess we'd need to determine which dimentions are important (and standardized ways to measure them).

hmmmm....