5 replies to this topic

[pSun]

Hello,

I have been driving a 1990 Plymouth Sundance for the past 8 weeks.  While not completey unfamiliar with the 2.5 liter (my wife drove an 89 Daytona back in the early 90's) my former mother in law was the original owner of this vehicle which in turn she sold to her man, who, became a close freind of many years; my daughter is 15 1/2 years old and driving on her permit so he suggested that the old Sundance may be the way to start her off, I agreed.

The original performance was substandard, 14.4 mpg in the city and barely able to pull any incline (compared to what I remember this car and the Daytona's power being back then), a full tune-up put things better on track, except for the handling.  Here is what I used for the "FULL" tune-up:

-E3 spark plugs
-MSD super coil
-sythetic oil and a PH8A (Ford Ranger size) oil filter, this adds close to a 1/2 quart capacity of oil to the system and the big filter catches a bunch of air to help cool it
-K+N air filter
-Dynomax cat back
-Taylor 8.2mm Lightning wires

This tune-up yeilded 20.6 mpg all city driving, so it was well worth the time, effort and money.  I would like to add that while the Dynomax cat-back only required some modest fabrication, it wasn't horrible but does rate mention for anyone concidering it.  I had to cut the exhaust at the joint prior to the muffler to get it apart.  I made 3 small cuts in the outer tubing, to pry it apart so as to not damage the tubing on the inside (the section comming from the cat).  The original tubing is 1 7/8th inside diameter (I.D.), so the kit provided a sleeve to fit over the stock section so that the Flowmaster piece could make the transistion without deforming it to make the seal.  I was impressed that they took this measure, I usually make my own exhausts so seeing any effort from an exhaust maufacturer to make the installation simple is something I truely appreciate.  On the other end (literally) for this particular chasis, the muffler and supplied parts wond up being approximently 4" shorter then necessary.  I slipped all the joints as far as I was comfortable and fabricated a hangar extension to fill the gap.

That was it for the install but I didn't like the exhaust note, neither did my daughter; it was very drone and a hair too loud (to me it sounded like a bad import exhaust verses a performance tuned exhaust).  I did some experimenting and found that if I changed the outlet from the 2 1/4 I.D. stuff to a dual outlet 1 3/4" piece (these used to be refered to as Monza tips) the sound was tamed and performance seemed unchanged.  When my former wife drove the Daytona, I used a similar exhaust tip and the engine realy perked up from just the exhaust tip, so I expected it would do well with the cat-back also.  The look from the bumper is what I would describe as time correct, possibly "retro".

I spent some time researching on this and other like forums; the results are that I can put a late 80's LeBaron convertable set of springs on the Sundance and possibly experience what I want for this car as my daughter's daily driver.

I aquired a set of 88 LeBaron convertable front and rear springs, it's 1.3" front swaybar, including a set of KYB GR-2 struts and a set of KYB Gas-a-just shocks from a 87 Lebaron T/C Wagon (all wrecking yard finds).  One of the struts was beyond use, the other had some life left in it.  Both of the shocks looked very new and have a ton of life left in them.  The springs, well I was uncertain how they would hold up but the Sundance's rear was sagging very bad and the struts were beyond safe use.

I installed the Gas-a-just's and the LeBaron's rear springs (same number of coils but an honest inch taller, uncompressed) all in one shot.  The difference was incredible; I had read that the springs used on these LeBarons were on par or superior to what Cadilac was using (at least in the same time period).  I have done a few suspensions and never enjoyed the ride as much as just doing the rear with these components.

Next I installed the 1.3" swaybar from the Lebaron with a set of bushings from "Polybushing.com".  This was also very rewarding, as the front now felt like a "bulldog", just flat, hardly any disernable body roll.  The struts and springs proved to be more work.  I received the KYB Excel-G struts from the KYB Outlet store online.  I was able to get the left one on yesterday but it took longer than I had alloted.  I did encounter a couple of setbacks.

1) the center nut was much harder to remove then the doner car's.  I soaked it in oil and failed several more times to make any progress with it.  My trusty, abused set of vice grips gave their last effort on this job; so I brought out their replacement.  A set of Craftsman Vice Grips that found in a garage sale.  I decided to find a snug socket to hold the strut rod end in place while I loosened the nut with the box wrench but I used the vice grips to hold the socket.  This worked.

2) the Lebaron springs had one (1) extra coil but were only about a honest inch taller, uncompressed.  I didn't feel this would work against me as it came off easy enough.  I was wrong.  I compressed 4 coils in the compression tool, then remove one side to grab 5 coils, to compress it enough to get the new nut on the Excel-G rod end.  This took quite a bit of time since I didn't have access to my air tools to work the strut spring compression tool.  I eventually had it all back together.
-NOTE: it is completely necessary to mark the location of the strut upper components prior to disassembly.  The book says to but I didn't fully understand why prior to doing it.  the location of the upper spring seat and the upper mounting plate are CRITICAL to proper strut alignment for reenstall.

I don't have the right side installed yet but I do have some immediate positive driving results (I had to drive my daughter to school this morning).  I had a "shimmy" in the suspension/drivetrain; i was uncertain whether it was an unbalanced wheel, missing wheel weight, worn suspension or steering components or a wheel bearing.  So I did what I always do, check the FREE fixes 1st.  I busted out the torque wrench, my books says to torque the lug nuts to 95ft/lbs; that helped but didn't fully eliminate the vibration.  Next, I took it to the exstablishment that installed the most recent tires.  A wheel weight had flung off; this helped but there remained a shimmy vibration which now felt like it was in the front.  I inspected the brakes, the are with spec and looked in good overall working order.  At this point I am crossing my fingers, since I was in the process of upgrading the suspension, I truely hoped that it would cure this as well.  The front sway bar install made the shimmy feel like the front left wheel was the predominant source of the vibration.  After installing the upgraded front left strut/spring, the shimmy is GONE!  Hurray!!!

Wheel bearings aren't the worst thing in the world to do but I reserve doing them until they are telling me they are failing.  So for now, it looks as though the bearings have some life left in them.  I will update this thread upon installation of the front right strut/spring.

If anyone has any questions or inputs regarding my selection of components, method of disassembly or my plan, I would like to encourage your inputs, thoughts and questions.  I am here to learn, everyonce in a while I accidentally do something right and from time to time I am able to share my experience with others or provide a laugh.

Edited by pSun, October 14, 2011 at 03:34 pm.

[SGspirit]

Thanks for writing all the interesting details.

[pSun]

-SGspirit; thanks for the feedback.

My daughter assisted me in making some time to complete the suspension install.  The right side strut and spring went in as easy as a breeze.  Everything I was foiled by on the other side brought me to a speedy completion.  I did a couple things different, they seem to be at least partly responsible for the decreased work time:

1) After taking apart the stock Sundance strut (to inspect and determine if any parts were reusable), I immediatly set the spring compressor to the new coil and at full compression.  I am uncertain but letting the spring sit while I monkeyed around inspecting, cleaning and lubricating seem to take a bit of spank of the springs ability to fight me during the install (this one went so much easier I have been grasping for the things that may have possibly made a difference).

2) while that spring sat and waited, I inspected the old upper and lower spring isolators, upper spring seat and strut bearing.  The Sundance didn't come with upper spring seat "bumpers" but the LeBaron convertable did (according to the Dodge bubbas, that means that the donor LeBaron had a special performance suspension package), so used the bumpers from the LeBaron verse paying $50 ea. from Dodge or $32 ea from Les Scwab.  After inspecting, cleaning and drying, I test fit them and lubed all the spring contact surfaces and the strut bearing contact surfaces with the super excellent Blue poylurethane grease that "Polybushings.com" supplied with their swaybar bushings (according to the website, it is included at no extra charge with every bushing purchase; I used it on the swaybar bushings and every point the front coil touches plus the upper strut bushing and only used half of the amount that was supplied).  The thing I did different on the right side was to lube the upper strut bushing contact surfaces; this seemed to make it much easier to tighten the strut bushing hold down nut (the main nut on the top of the strut pack).

3) the last thing I did different, since I wasn't rushing, I took a hard look at where the bottom fastener goes through the strut to the "A" arm.  I finally understood what I was supposed to mark down there prior to dissasembly but I was installing new struts with intensions to set the maximum negative camber (this was suggested to aid in turning).  On the left side I attempted to follow the book an set it up like the old strut.  This resulted in a positive camber, very positive; it pulled to the left almost enough to make a 90 degree left turn unassisted.  So on the right I slid the bottom bolt all the way outboard in the adjustment slot, which I hypothisized would result in max negative camber.  I was fortunate and made the correct guess.  I test drove it like this to see what max neg on the right and a very positive on the left felt like...not a desirable feeling.  After the around the block, I popped off the left wheel, loosened the 2 bottom end fasteners and reset the left strut for maximum negative camber also.  This resulted in a slight increase in the pressure required to initiate a turn but once commited to it the car felt like it was on AUTO turn.  I have not pushed this setup in and out of turns yet but when my daughter test drove it she noticed the same thing (unprompted).  She said it took a bit more effort to start a slow speed turn but then the remainder of the turn was very motivated requiring very little input.

I have not pushed this suspension in any way after the full install but will check it at highway speeds this weekend and share the results.  I can say that the front spring/strut combo was the least dramatic change.  It made all the bad stuff disapeared; the shimmy, the multiple front end bounce, the pogo during bumps on freeway turns and a general free-for-all body roll contest winner.  In other words, it still is no race setup but without question, an improvement over the stock components, I dare say, even when they were new (not withstanding that the springs and bar were a 23 year old wrecking yard pull).  It feels very flat, firm but generally forgiving on straits.  When asked to turn it pulls into the turn much more agressive, so I have to call this successful.

Next I am going to determine what the best size tire to use with the 01-03 Sebring 12 spokes I intend to lace on it.  So far I am sold on what ever is nearest the 225x50-15 used on the 89 Daytona Shelby Z.  If I am not mistaken the diameter needs to be close to 23.4".  Please feel free to offer suggestions regarding the best size 16" rubber to use for optimum fuel economy with my setup.

Edited by pSun, October 14, 2011 at 11:54 pm.

[pSun]

This car needed some suspension help, I am pleased to learn that so many used parts are out there and still so useful for someone who doesn't like to just drop $1,000 at the garage everytime their auto makes a new sound.

RESULTS: the rear coils are taller with the same number of coils while the front had an extra coil and about an inch taller (unsprung).  The overall driving experience is at a much higher level; the Gas-a-just KYB's do a very good job of controling the LeBaron rear coils which have a higher spring rate.  The front LeBaron coils are also much firmer but the KYB GR-2 front struts let them work providING more extend control then retract.  Overall a very good balanced system: notworthy is that the addition of the 1.3" front sway bar from the 88 LeBaron convertable is what brought the whole thing together.

Cost of parts:
88 LeBaron converatble front coils, $50
88 LeBaron convertable rear coils, $20
88 LeBaron convertable 1.3" anti-sway bar, $10
Polybushings.com sway bar bushings, $32
KYB GR-2 front struts, $82 (for the pair)
KYB Gas-a-just rear shocks, $20 (from a 87 LeBaron T/C wagon)

total, $214, rides like a dream and my daughter now knows what each part of the suspension does for ride control.

I hope my experience is useful for another potential suspension job.

Edited by pSun, October 17, 2011 at 09:22 am.

[StarFire_MK2]

pSun:
Thanks for a very informative write-up! My 87 Sundance needs a new suspension in the spring (actually, it needs one now but I can't justify the cost...money is really tight now), and I'll be using your tips to do the work.

A question: you mention the rear LeBaron springs were an inch taller than stock Sundance ones. Did you encounter any problems with installing them?

[pSun]

StarFire_MK2- sorry for the delay in my response (LIFE).  I did the whole proceedure in my driveway with the stock scissor jack some scrape pieces of 8x12" lumber and rocks to chock the front wheels in place (for safety).  I did one side at a time to completion and do have some photos if you are interested.

-To specifically address your question, the answer is yes.  Where the stock, poorly sagging coils just about fell from their perches, the 1988 LeBaron rear coils required me to physically compress them by hand, just a bit to POP them into the perches.  It wasn't a "TOTAL, ALL MY POSIBLE STREGNTH" type move; I was lying on the cement with very poor leverage and a decent grip with one hand and marginal grip with the other not exerting full strength but taking the necessary caution not to get one or both hands caught in there with the coil.  I had enough room, if I had wanted to simply/safely PLOP them in, I suppose a spring compressor would be the prudent solution (compressing approximently 1/8 to 3/16" total and just for a moment.  I was some effort but I managed as I have detailed and lost no new paint from the coils while doing so.

Proceed without fear my friend!    The undercarige of the Sundance shows alot and from many angles do to the ride hieght; it looks very refreshing underneath.  I still haven't learned how to post photos, so unless someone wants to walk me through it, I will link my PHOTOBUCKET upon request (I look under this car everyday when I pull in the driveway, it is dead sexy!! ...yet the looks nowhere compare to the FEELING.