New to me 1991 235k has hard ride and need service advice (1 Viewer)

[anonymous]

Hi, I just picked up a new 1991 FJ with 235 k, everything works, but I have a few oil leaks, suspect bad engine mounts, the truck shifts promptly but a bit hard, also the ride is rough and a bit scary and unstable at high speed, it's got emu springs with 863 on the back and J springs on the front and otherwise stock original suspension, engine runs strong but idles a bit unstable.

I am planing to rebuild the front end, service the trans and transfer case, service the rear end and cooling system?

What else should be done?

What can I do to improve the harsh ride, do the springs have to go?

When I say harsh ride I mean stiff, it is as stiff as my lowered sports car with 40 series tires.

I will get the fsm when possible.

Thanks for the advice.

 

[flow]

Welcome I can help point you in the right direction on a couple of those issues:

the hard shifting is pretty common on these trucks. Greasing the driveshafts helps but check your u-joints to see if theyre worn out first.

The rough ride is due to the heavy load springs front and rear.Change your springs if you dont plan to use your truck for heavy hauling. See this:
OME COIL SPRINGS

With that lift, you will need a castor correction kit to get rid of the nervousness in the steering. Slee Off Road makes a kit as well as some others.

Look up info on how to "Baseline" you rig. There are lots of good threads about how to bring your truck into great working condition that is totally reliable. Look into the Pain-in-the-a$$ factory EGR emissions system plumbing for problems with idle and CELs (check engine lights).

CHeck this out:
IH8MUD Forum - Announcements in Forum : 80-Series Tech
and you can find a lot of great info well documented here:
https://forum.ih8mud.com/80-series-...2011-added-concretejungles-1fze-overhaul.html

You will find that this forum is a gold mine for info about our trucks. Lots of procedures, tips, and pictures have been added over the years so make sure you search thoroughly before asking or you may just hear crickets.

 

[Michael Hanson]

Personally My ride is firm,how are the seats, original? Replace the cushions. Mike

 

[coax]

also the ride is rough and a bit scary and unstable at high speed, it's got emu springs with 863 on the back and J springs on the front and otherwise stock original suspension.

Are you saying it has stock Toyota shocks on there still with stock castor bushings? If so, either of those could cause a horrible ride coupled with 850j/863 springs. (IE way out of spec castor and/or very small amounts of wheel droop/downtravel).

 

[anonymous]

Thanks to all who have responded, will look up "baselining".

The suspension is completly stock and original with the exeption of the springs.


I have read elsewere on this forum in searching, that the only differences between the EMU springs are the lengths, if thats correct can I just cut the spring down to the uncompressed length of the standard EMU springs, and would that improve the ride, what I am reading between the lines is that the ride issues are due to spring length and not spring rate.

Are you saying it has stock Toyota shocks on there still with stock castor bushings? If so, either of those could cause a horrible ride coupled with 850j/863 springs. (IE way out of spec castor and/or very small amounts of wheel droop/downtravel).

 

[coax]

what I am reading between the lines is that the ride issues are due to spring length and not spring rate.

Its a combination of everything. The spring rate is definitely higher than the OEM springs, which will contribute to a stiffer ride, especially if you have no extra weight in the cruiser. Castor out of spec is gonna make you swerve and wander all over the road, and shocks not matched to springs are gonna do crazy things too. All of that is going to contribute to a poor ride.

If your goal is to return to stock, you could sell the OME springs and pick up some used toyota ones and probably come out well ahead.

 

[anonymous]

Thanks for the advice:

I am going to try and find stock springs for now.

Could the rig be topping out on the shocks?

 

[coax]

Could the rig be topping out on the shocks?

Its very possible. You'd want to confirm by measuring, but IIRC the OEM shocks are aprox. 22.5" extended in the front. For reference when I had my 850 springs on the front (1" less than J's) PLUS the Nitrocharger n73's that are just over 24" extended, I had aprox. 3.5" of extension left. Factor in your increased lift (1") and reduced shock length(1.5") and you are in the area of 1" of downtravel.

 

[mikgrail3]

A great guide (with part #'s) is this tune up sheet from John Held for the 3FE - http://www.sdsysdesign.com/tlc/images/Strife/3FE TuneUp.pdf

Here's a link to the 3FE tune up thread: https://forum.ih8mud.com/80-series-tech/270758-general-3fe-tune-up-info.html

Also, with an unstable idle, make sure all your vaccuum lines are in good shape and routed properly. Theres a diagram sticker under the hood. Plus make sure the air intake hose is solid with no cracks. The 3FE is very sensitive to unmetered air. I just recently replaced a leaking brake booster and in doing so fixed a low idle condition because of the vaccuum leak.

Good luck and congrats!

 

[Kalawang]

I'm thinking your shocks are either busted or wrong size and possibly stiffness and causing a harsh ride. Your cheapest check is to remove the shocks entirely and check the ride driving SLOWLY in an open area. If you get a boaty ride, it should be proof you need new shocks. It's also an indication you need stiffer springs. The ride should feel pretty close to normal and comfy.

Good lift springs always come a lot stiffer than stock length springs. That's to help reduce sway. It also helps much to install stiff shocks, stiffer than stock height, to also reduce sway. Flex will be there regardless and it's possible you might even make the mistake of thinking you don't need shocks. Don't. The shocks will keep your tires and ride from dribbling like a basketball if you hit something at speed and also act as limiters if you accidentally go flying over a hill top thereby keeping your springs and other parts from being torn off from stress they were not designed to endure.

Uncertain steering can be caused by slightly unbalanced wheels, though you normally know this by the vibration they induce. A more subtle cause could be worn out tie rod ends. Best check is to pull them out and see if they are too soft or even lollygagging. If you can move those ends by hand, they are too soft.

One thing I neglected to mention here is tire condition.

Overly inflated tires can cause a harsh ride, and having a tire inflated significantly different from the other tires can cause uncertain steering. This is the cheapest check of them all and should be your very first test.


Kalawang