- Air Filters
- Skip Shift (CAGS)
- M6 Shifter Install
- Rear Differential
- Oil and Filters
Air Filters
Air Filter Replacements
If you are interested in improving the flow of inducted air into your new LS1, you can replace the stock filter with one of several replacements. K&N, Fram, and Purolator make filters which will fit your stock airbox. Installation can be completed in under 10 minutes, and the cost is minimal. K&N does not endorse the use of their product in LS1 F-Body applications at this point. If you aren't concerned with this detail, the K&N will improve air flow into your LS1. Other standard filter replacements are also detailed below. The K&N Filter is the most expensive, costing about $50. I would like to note that there is an ongoing debate about the effectiveness of the K&N filter replacement.
| Filter
|
Part Number
|
| K&N High Flow
|
33-2014
|
| Fram
|
CA3914
|
| Purolator
|
A34333
|
| Wix
|
46144
|
Air Filter Box Modifications
MTI has designed an alternate hood for the LS1 airbox. This hood simply replaces the stock hood and relocates the air temperature sensor in the new hood. There is much debate about the effectiveness of this particular modification, but first hand experience has shown about half of the advertised gain. For some LS1 f-body applications, no gain has been seen. You may see a maximum of 10 RWHP (rear wheel horsepower) from this high flow induction hood.
CAGS
What is it?
Applicable to 6 speed manual transmissions. CAGS eliminates the annoying interaction of the Skip Shift solenoid during shifting. The solenoid is removed from the system, eliminating the requirement to slow down, speed up or shift into 4th gear from first. I think GM did this to avoid the "gas guzzler" tax, but it can be a very real safety hazard. The CAGS Skip Shift Eliminator does not affect the Skip Shift indicator on the dash. You will however, be free to shift from first to second without regard to engine temperature, rate of acceleration and engine speed.
How do you eliminate it?
The easiest way to eliminate the CAGS is to purchase the CAGS plug and wiring harness from a reputable company. They can be found for as little as $25. Installation will take about 30 minutes due to having to access the CAGS solenoid in the front left of the transmission under the car. You will need to elevate the front of the car in some way to comfortably install the plugs. Once under the car, you can do this mod in about ten minutes. Important, make sure you identify the CAGS solenoid first, as there are several other solenoids in the immediate area.
If you are one one of those conservative types who wants to keep all your cash for the next life, you can perform this mod without the CAGS plug mentioned above. The CAGS procedure is described right here.
Installation of an Aftermarket Shifter
Basically, these directions will apply to any aftermarket shifter installation for the new 1998 LS1 f-body. You will first need to raise the arm rest and remove the two bolts in the bottom of the storage area. There are two more bolts, one on each side of the center console in the very front down near the carpet. Remove these and set them aside. Since the ashtray contains a light, you will need to remove it and disconnect the light assembly. Remove the ashtray light by sliding it out of the assembly, and lay it aside. You will find another bolt hidden beneath the ashtray which also need to be removed. At this point, unscrew the shifter knob and retain for use on the new shifter, unless you have purchased a new shifter knob.
Next, you need to remove the upper portion of the console, by sliding it backwards towards the rear seats. Now you are ready to pull the parking brake lever up as far as you can. The closer to vertical you get the lever, the better. You should now remove the lower portion of the console by lifting it up in the rear over the emergency brake. You should now have a totally unobstructed view of the shifter retainer boot.
Now remove the stock shifter lever by removing the two hex screws on the side near the bottom. Now remove the six bolts which retain the shifter boot in place. You may have to slightly pry on the boot to free it from the assembly once the bolts are removed. You can now remove the four bolts holding the stock shifter in place. Remove the stock shifter and remove all the old sealant around the top of the metal housing where the new shifter will be placed. Make sure the bushing below the old stock shifter is well greased. If the car is relatively new, you can remove the grease from the old shifter, and lubricate the bushing as well as the mating ball on your new shifter. You will now need to place a bead of RTV sealant around the base of the shifter mount, I personally prefer the black variety as opposed to the clear type.
Mount the new shifter in place atop the bead of RTV. Secure the shifter with the four bolts supplied, or simply use the old ones if new ones weren't included. You will now need to adjust the shift stops on your new shifter. Follow the recommendations included with your shifter. Replace the stock boot and the new silencer which came with your shifter. You may at this point reassemble the console and complete the installation.
Rear Differential
Differential Fluid Change
You will need a 13mm socket or wrench, a 3/8 drive ratchet, at least 1bottle of GM approved limited slip additive, a little more than 2 quarts of GM approved rear differential lubricant, a gasket (GM part number 26016661), gasket sealer, a wide drain pan, oil soak, plenty of shop towels and some sort of cleaner for the differential carrier and backing plate.
Let me start by saying you will get lubricant on the floor, right where you are. It's unavoidable. If you have been driving your car for any length of time, the lube will be hot, so please be careful and have the oil soak and shop towels handy. Also chock the wheels if you aren't using a lift. Leave the transmission in neutral. Remember to use automotive jack stands rated to withstand the weight of your car.
Begin by orienting the gasket with the bolts, making sure it is the CORRECT gasket. Next, remove the bolts that hold the backing plate. Notice that there are 2 brackets that also use these bolts. They anchor the brake lines. These bolts are slightly longer than the others, so pay attention to this during reassembly. As soon as you get the bolts out of the bottom, you should begin to see some dripping. So have the drain pan ready. When all the bolts are out, gently pry or tap the backing plate to get it off. Hang on to it, or it'll wind up in your drain pan. The lubricant should flow out of the housing rather quickly and with a big splash. If you use any oil soak, keep the dust to a minimum as it will get inside your differential housing.
Now its time to clean everything. I personally use spray carb cleaner. It sprays out of the can with some velocity, cuts grease very well, doesn't harm soft materials like seals and gaskets and evaporates rather quickly. But it's flammable, so be careful. Soak the inside of the housing and the carrier first and then spin the rear wheels to get to the other side of the carrier (the reason for leaving the car in neutral). Wipe out all the material from the bottom of the housing, using paper towels. Repeat this a couple of times until you are satisfied it's all clean. This usually takes a couple of cans of cleaner.
Do the same to the backing plate. Notice what looks like a big washer attached to the plate? That's a magnet and is glued to the plate. Don't try and remove it. Just hose it and the inside of the plate down with carb cleaner and wipe several times until it is clean. Make sure the old gasket is COMPLETELY removed from both the housing and backing plate.
Orient the plate (the magnet goes towards the bottom) and smear a narrow, even coat of gasket sealer all the way around the plate making sure you get sealer on both sides of the bolt holes. Place the gasket onto the backing plate, aligning the gasket with the bolt holes. Smear another narrow bead onto the gasket following the same procedure.
Put 2 bolts into the backing plate, one on each lower side (remember the magnet goes down) and carefully replace the backing plate. Remember the 2 longer bolts go with the brake line brackets and the backing plate is notched to accommodate them. Don't over tighten the bolts and don't forget to replace the additive and lubricant.
Use a 3/8 drive ratchet to remove the fill level check plug on the right front of the differential housing. Add the additive first and then fill with the lubricant. This can be tricky, messy and frustrating. A small funnel with a clear tube attached ensures that you can see the lube flowing. Once full, replace the plug and you are finished.
Drive slowly for a couple of miles, allowing the additive and lubricant to mix thoroughly. Stop and check for leaks and after a few miles check the differential level again.
Try using a squeeze bottle with a long nipple to add the fluid. You can pour the additive into the bottle along with the fluid and shake them until mixed. Then use a section of clear motorcycle gas line clamped over the nipple to stick into the rear differential fill hole. This filling method saves a lot of spills and keeps your blood pressure within safe levels.
This author accepts neither responsibility nor liability for any damage caused by this procedure. Anyone deciding to perform this procedure does so at their own risk.
Oil and Oil Filters
Filters
Included in the table below, you will find a listing of oil filters that will work on the 98 LS1. An 'L' denotes the large version of the filter. Please note that the original owners manuals incorrectly listed a PF24 oil filter for the LS1. This was later corrected by an addendum to the manual which was mailed to all LS1 owners.
- AC Delco PF44
- AC Delco PF58 (L)
- Amsoil ASF 30 (L)
- Deutsch 377
- Fram PH 3506
- Fram PH 3675 (L)
- Hard Driver HD08 (L)
- Mobil 1 M1-107
- Mobil 1 M1-206 (L)
- Motorcraft FL-331 (L)
- NAPA 1045 (L)
- PureOne PL20123 (L)
- Purolator L14006
- Purolator L20123 (L)
- Purolator L24007 (slightly larger)
- WIX 51045 (L)
Oil
While oil selection is often a matter of personal preference, GM recommends a synthetic 5W30 in the owners manual. Most LS1 owners opt for the Mobil 1 5W30 or 10W30 variety. You can usually obtain a 6 quart case of Mobil 1 for around $25.
